Junior Subordinated Debentures Issued to Capital Trusts - Schedule of Outstanding Junior Subordinated Debentures and Related Trust Preferred Securities Issued by Each Trust (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012
Financial Instruments Subject to Mandatory Redemption by Settlement Terms [Line Items]
Carrying value	$ 41,089	$ 188,522
GCB Capital Trust III [Member]
Financial Instruments Subject to Mandatory Redemption by Settlement Terms [Line Items]
Annual interest rate, base rate	3-month LIBOR
Annual interest rate spread, percentage	1.40%
Trust Preferred Securities Subject to Mandatory Redemption [Member] | State Bancorp Capital Trust I [Member]
Financial Instruments Subject to Mandatory Redemption by Settlement Terms [Line Items]
Face value	10,000	10,000
Annual interest rate, base rate	3-month LIBOR
Annual interest rate spread, percentage	3.45%
Issuance date	October 29, 2002
Distribution dates	Quarterly
Trust Preferred Securities Subject to Mandatory Redemption [Member] | State Bancorp Capital Trust II [Member]
Financial Instruments Subject to Mandatory Redemption by Settlement Terms [Line Items]
Face value	10,000	10,000
Annual interest rate, base rate	3-month LIBOR
Annual interest rate spread, percentage	2.85%
Issuance date	December 19, 2003
Distribution dates	Quarterly
Trust Preferred Securities Subject to Mandatory Redemption [Member] | GCB Capital Trust III [Member]
Financial Instruments Subject to Mandatory Redemption by Settlement Terms [Line Items]
Face value	24,000	24,000
Annual interest rate	6.96%
Issuance date	July 2, 2007
Distribution dates	Quarterly
Subordinated Debentures Subject to Mandatory Redemption [Member] | State Bancorp Capital Trust I [Member]
Financial Instruments Subject to Mandatory Redemption by Settlement Terms [Line Items]
Carrying value	8,424	8,300
Contractual principal balance	10,310	10,300
Annual interest rate, base rate	3-month LIBOR
Annual interest rate spread, percentage	3.45%
Stated maturity date	Nov. 07, 2032
Initial call date	Nov. 07, 2007
Subordinated Debentures Subject to Mandatory Redemption [Member] | State Bancorp Capital Trust II [Member]
Financial Instruments Subject to Mandatory Redemption by Settlement Terms [Line Items]
Carrying value	7,683	7,600
Contractual principal balance	10,310	10,300
Annual interest rate, base rate	3-month LIBOR
Annual interest rate spread, percentage	2.85%
Stated maturity date	Jan. 23, 2034
Initial call date	Jan. 23, 2009
Subordinated Debentures Subject to Mandatory Redemption [Member] | GCB Capital Trust III [Member]
Financial Instruments Subject to Mandatory Redemption by Settlement Terms [Line Items]
Carrying value	24,982	25,100
Contractual principal balance	$ 24,743	$ 24,700
Annual interest rate	6.96%
Stated maturity date	Jul. 30, 2037
Initial call date	Jul. 30, 2017