Loans and Allowance for Loan Losses Recorded Investment in Loans Modified in TDRs within Previous 12 months Subsequently Defaulted (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Financing Receivable, Modifications [Line Items]
Financing receivable modifications recorded investment subsequently defaulted	$ 790	$ 14,096	$ 1,374	$ 20,113
Premium wine
Financing Receivable, Modifications [Line Items]
Financing receivable modifications recorded investment subsequently defaulted				0
Commercial Portfolio Segment | Software and internet
Financing Receivable, Modifications [Line Items]
Financing receivable modifications recorded investment subsequently defaulted	0	11,107	584	17,124
Commercial Portfolio Segment | Hardware
Financing Receivable, Modifications [Line Items]
Financing receivable modifications recorded investment subsequently defaulted	0	2,031	0	2,031
Commercial Portfolio Segment | Life science/healthcare
Financing Receivable, Modifications [Line Items]
Financing receivable modifications recorded investment subsequently defaulted	0	958	0	$ 958
Commercial Portfolio Segment | Premium wine
Financing Receivable, Modifications [Line Items]
Financing receivable modifications recorded investment subsequently defaulted	$ 790	$ 0	$ 790