Income Taxes (Details Textual) - USD ($) $ in Thousands, shares in Millions		12 Months Ended
	Oct. 06, 2015	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Taxes Payable, Current		$ 38,900	$ 98,800
Deferred Tax Assets, Valuation Allowance		78,407	94,120
Unused Federal operating loss carryforwards		0
Unused State operating loss carryforwards		1,100,000
Unused Federal capital loss carryforwards		100
Deferred Tax Assets, Tax Credit Carryforwards, Foreign		5,200
Unrecognized Tax Benefits that Would Impact Effective Tax Rate		5,806	6,443
Significant Change in Unrecognized Tax Benefits is Reasonably Possible, Amount of Unrecorded Benefit			5,300
Unrecognized Tax Benefits, Income Tax Penalties and Interest Expense		200	(200)	$ (600)
Unrecognized Tax Benefits, Income Tax Penalties and Interest Accrued		800	500
Effective Income Tax Rate Reconciliation, Change in Deferred Tax Assets Valuation Allowance, Amount		$ (15,721)	$ (13,071)	$ (8,689)
Effective Income Tax Rate Reconciliation, Change in Enacted Tax Rate, Percent		21.00%	35.00%	35.00%
Valuation Allowance, Deferred Tax Asset, Increase (Decrease), Amount		$ 15,700
Minimum [Member]
State operating loss carryforwards expiration date		Dec. 31, 2019
Open Tax Year		2011
Maximum [Member]
State operating loss carryforwards expiration date		Dec. 31, 2038
Federal capital loss carryforward expiration date		12/31/2021
Foreign tax credit carryforward expiration date		Dec. 31, 2021
Open Tax Year		2017
State and Local Jurisdiction [Member] | Minimum [Member]
Income Tax Examination, Year under Examination		2012
State and Local Jurisdiction [Member] | Maximum [Member]
Income Tax Examination, Year under Examination		2016
Internal Revenue Service (IRS) [Member] | Minimum [Member]
Income Tax Examination, Year under Examination		2011
Internal Revenue Service (IRS) [Member] | Maximum [Member]
Income Tax Examination, Year under Examination		2012
Shares Of Common Stock [Member] | Square 1 Financial, Inc. [Member]
Stock Issued During Period, Shares, New Issues	18.1
LIHTC Investments [Member]
Tax Credit Carryforward, Amount		$ 14,000
Other Tax Expense (Benefit)		8,400
Income Tax Expense [Member] | LIHTC Investments [Member]
Amortization		11,900	$ 6,300
Foreign Tax Credit [Member]
Valuation Allowance, Deferred Tax Asset, Increase (Decrease), Amount		4,100
Expires 2018 [Member]
Valuation Allowance, Deferred Tax Asset, Increase (Decrease), Amount		$ 11,600