CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Statement of Comprehensive Income [Abstract]
Net income	$ 194,244	$ 147,951	$ 114,965
Other Comprehensive Income (Loss), Transfers from Held-to-maturity to Available-for-Sale Securities, Net of Tax	0	8,976	0
Other comprehensive income (loss), net:
Unrealized (loss) gain on AFS securities, net of tax effect of $3,922, $(17,749), and $18,240, respectively	(6,117)	29,683	(30,503)
Unrealized Gain (Loss) on Cash Flow Hedging Instruments	0	0	(17)
Other Comprehensive (Income) Loss, Pension and Other Postretirement Benefit Plans, Adjustment, Net of Tax	90	0	0
Other Comprehensive Income (Loss), Unrealized Holding Gain (Loss) on Subordinated Debt	(4,276)	0	0
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability, Gain (Loss) Included in Other Comprehensive Income (Loss)	(4,276)
Fair Value, Liabilities Measured on Recurring Basis, Change in Unrealized Gain (Loss)	(6,523)	1,380	(5,900)
Realized (gain) loss on sale of AFS securities included in income, net of tax effect of $230, $283, and $(447), respectively	(385)	(474)	748
Net other comprehensive (loss) income	(10,688)	38,185	(29,772)
Comprehensive income	$ 183,556	$ 186,136	$ 85,193