SCHEDULE 13G

Amendment No. 3
SVB Financial Group
Common Stock
Cusip #78486Q101

Cusip #78486Q101
Item 1:	Reporting Person - FMR Corp.
Item 4:	Delaware
Item 5:	377,250
Item 6:	0
Item 7:	3,506,382
Item 8:	0
Item 9:	3,506,382
Item 11:	9.989%
Item 12:	    HC

Cusip #78486Q101
Item 1:	Reporting Person - Edward C. Johnson 3d
Item 4:	United States of America
Item 5:	0
Item 6:	0
Item 7:	3,506,382
Item 8:	0
Item 9:	3,506,382
Item 11:	9.989%
Item 12:	IN



	SCHEDULE 13G - TO BE INCLUDED IN STATEMENTS
	FILED PURSUANT TO RULE 13d-1(b) or 13d-2(b)

This filing has been made to amend a previous filing made as of
December 31, 2005.  This is due to a corrected shares outstanding
figure.


Item 1(a).	Name of Issuer:

		SVB Financial Group

Item 1(b).	Name of Issuer's Principal Executive Offices:

		3003 Tasman Drive
		Santa Clara, CA  95054


Item 2(a).	Name of Person Filing:

		FMR Corp.

Item 2(b).	Address or Principal Business Office or, if None, Residence:

		82 Devonshire Street, Boston, Massachusetts  02109

Item 2(c).	Citizenship:

		Not applicable

Item 2(d).	Title of Class of Securities:

		Common Stock

Item 2(e).	CUSIP Number:

		78486Q101

Item 3.	This statement is filed pursuant to Rule 13d-1(b) or 13d-2(b) and
the person filing, FMR Corp., is a parent holding company in accordance
with Section 240.13d-1(b)(ii)(G).  (Note:  See Item 7).

Item 4.	Ownership

(a)	Amount Beneficially Owned:	3,506,382

(b)	Percent of Class:	9.989%

(c)	Number of shares as to which such person has:

(i)	sole power to vote or to direct the vote:	377,250

(ii)	shared power to vote or to direct the vote:	0

(iii)	sole power to dispose or to direct the disposition of:	3,506,382

(iv)	shared power to dispose or to direct the disposition of:	0



Item 5.	Ownership of Five Percent or Less of a Class.

	Not applicable.

Item 6.	Ownership of More than Five Percent on Behalf of Another Person.

	Various persons have the right to receive or the power to direct
	the receipt of dividends from, or the proceeds from the sale of,
	the Common Stock of SVB Financial Group.  No one person's interest
	in the Common Stock of SVB Financial Group is more than five percent
	of the total outstanding Common Stock.

Item 7.	Identification and Classification of the Subsidiary Which Acquired
	the Security Being Reported on By the Parent Holding Company.

	See attached Exhibit A.

Item 8.	Identification and Classification of Members of the Group.

	Not applicable.  See attached Exhibit A.

Item 9.	Notice of Dissolution of Group.

	Not applicable.

Item 10.Certification.

	By signing below I certify that, to the best of my knowledge and
	belief, the securities referred to above were acquired in the
	ordinary course of business and were not acquired for the purpose
	of and do not have the effect of changing or influencing the control
	of the issuer of such securities and were not acquired in connection
	with or as a participant in any transaction having such purpose or
	effect.

	Signature

	After reasonable inquiry and to the best of my knowledge and belief,
	I certify that the information set forth in this statement is true,
	complete and correct.

	February 24, 2006
	Date

	/s/Eric D. Roiter
	Signature

	Eric D, Roiter
	Duly authorized under Power of Attorney
	dated December 30, 1997 by and on
	behalf of FMR Corp. and its direct
	and indirect subsidiaries

	SCHEDULE 13G - TO BE INCLUDED IN STATEMENTS
	FILED PURSUANT TO RULE 13d-1(b) or 13d-2(b)



	Pursuant to the instructions in Item 7 of Schedule 13G, Fidelity
	Management & Research Company ("Fidelity"), 82 Devonshire Street,
	Boston, Massachusetts 02109, a wholly-owned subsidiary of FMR Corp.
	and an investment adviser registered under Section 203 of the
	Investment Advisers Act of 1940, is the beneficial owner of
	3,131,982 shares or 8.922% of the Common Stock outstanding of SVB
	Financial Group  ("the Company") as a result of acting as investment
	adviser to various investment companies registered under Section 8
	of the Investment Company Act of 1940.

	Edward C. Johnson 3d and FMR Corp., through its control of Fidelity,
	and the funds each has sole power to dispose of the 3,131,982 shares
	owned by the Funds.

	Members of the family of Edward C. Johnson 3d, Chairman of FMR Corp.,
	are the predominant owners, directly or through trusts, of Series B
	shares of common stock of FMR Corp., representing 49% of the voting
	power of FMR Corp.  The Johnson family group and all other Series B
	shareholders have entered into a shareholders' voting agreement under
	which all Series B shares will be voted in accordance with the
	majority vote of Series B shares.  Accordingly, through their
	ownership of voting common stock and the execution of the
	shareholders' voting agreement, members of the Johnson family may be
	deemed, under the Investment Company Act of 1940, to form a
	controlling group with respect to FMR Corp.

	Neither FMR Corp. nor Edward C. Johnson 3d, Chairman of FMR Corp.,
	has the sole power to vote or direct the voting of the shares owned
	directly by the Fidelity Funds, which power resides with the Funds'
	Boards of Trustees.  Fidelity carries out the voting of the shares
	under written guidelines established by the Funds' Boards of Trustees.

	Fidelity Management Trust Company, 82 Devonshire Street, Boston,
	Massachusetts 02109, a wholly-owned subsidiary of FMR Corp. and a
	bank as defined in Section 3(a)(6) of the Securities Exchange Act of
	1934, is the beneficial owner of  174,400 shares or 0.497% of the
	Common Stock outstanding of the Company as a result of its serving as
	investment manager of the institutional account(s).

	Edward C. Johnson 3d and FMR Corp., through its control of Fidelity
	Management Trust Company, each has sole dispositive power over
	174,400 shares and sole power to vote or to direct the voting of
	174,400 shares of Common Stock owned by the institutional account(s)
	as reported above.

	Fidelity International Limited ("FIL"), Pembroke Hall, 42 Crow Lane,
	Hamilton, Bermuda, and various foreign-based subsidiaries provide
	investment advisory and management services to a number of non-U.S.
	investment companies and certain institutional investors.  FIL, which
	is a qualified institution under section 240.13d-1(b)(1) pursuant to
	an SEC No-Action letter dated October 5, 2000, is the beneficial
	owner of 200,000 shares or 0.570% of the Common Stock outstanding of
	the Company.

	A partnership controlled predominantly by members of the family of
	Edward C. Johnson 3d, Chairman of FMR Corp. and FIL, or trusts for
	their benefit, owns shares of FIL voting stock with the right to cast
	approximately 38% of the total votes which may be cast by all holders
	of FIL voting stock.  FMR Corp. and FIL are separate and independent
	corporate entities, and their Boards of Directors are generally
	composed of different individuals.

	FMR Corp. and FIL are of the view that they are not acting as a
	"group" for purposes of Section 13(d) under the Securities Exchange
	Act of 1934 (the "1934" Act) and that they are not otherwise required
	to attribute to each other the "beneficial ownership" of securities
	"beneficially owned" by the other corporation within the meaning of
	Rule 13d-3 promulgated under the 1934 Act.  Therefore, they are of
	the view that the shares held by the other corporation need not be
	aggregated for purposes of Section 13(d). However, FMR Corp. is
	making this filing on a voluntary basis as if all of the shares are
	beneficially owned by FMR Corp. and FIL on a joint basis.


	SCHEDULE 13G - TO BE INCLUDED IN STATEMENTS
	FILED PURSUANT TO RULE 13d-1(b) or 13d-2(b)
	RULE 13d-1(f)(1)  AGREEMENT

	The undersigned persons, on February 24, 2006, agree and consent to
	the joint filing on their behalf of this Schedule 13G in connection
	with their beneficial ownership of the Common Stock of SVB Financial
	Group at December 31, 2005.

	FMR Corp.

	By /s/ Eric D. Roiter
	Eric D. Roiter
	Duly authorized under Power of Attorney
	dated December 30, 1997, by and on behalf
	of FMR Corp. and its direct and indirect
	subsidiaries

	Edward C. Johnson 3d

	By /s/ Eric D. Roiter
	Eric D. Roiter
	Duly authorized under Power of Attorney
	dated December 30, 1997, by and on behalf
	of Edward C. Johnson 3d

	Fidelity Management & Research Company

	By /s/ Eric D. Roiter
	Eric D. Roiter
	Senior V.P. and General Counsel