Unaudited Condensed Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Statement of Comprehensive Income [Abstract]
Net income	$ 30,957	$ 29,614	$ 90,090	$ 86,619
Other Comprehensive (Loss) Income, Net of Tax
Unrealized (losses) gains on available-for-sale securities	(9,945)	11,506	30,614	(9,063)
Reclassification adjustment for losses included in net income	594	50	651	95
Net unrealized (losses) gains on available-for-sale securities	(9,351)	11,556	31,265	(8,968)
Tax effect	3,624	(4,476)	(12,111)	3,502
Net of tax amount	(5,727)	7,080	19,154	(5,466)
Unrealized gains (losses) on derivatives used for cash flow hedges	1,959	(8,630)	(11,989)	(10,727)
Reclassification adjustment for losses included in net income	1,555	1,263	4,962	3,771
Net unrealized gains (losses) on derivatives used for cash flow hedges	3,514	(7,367)	(7,027)	(6,956)
Tax effect	(1,362)	2,854	2,722	2,685
Net of tax amount	2,152	(4,513)	(4,305)	(4,271)
Total other comprehensive (loss) income, net of tax	(3,575)	2,567	14,849	(9,737)
Total Comprehensive Income	$ 27,382	$ 32,181	$ 104,939	$ 76,882