Unaudited Condensed Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Statement of Comprehensive Income [Abstract]
Net income	$ 52,392	$ 44,384	$ 101,524	$ 82,943
Other Comprehensive Income (Loss), Net of Tax
Unrealized gains (losses) on available-for-sale securities	29,877	(6,696)	76,329	(32,407)
Reclassification adjustment for (gains) losses included in net income	(134)	64	(355)	346
Net unrealized gains (losses) on available-for-sale securities	29,743	(6,632)	75,974	(32,061)
Tax effect	(7,537)	1,681	(19,252)	8,125
Net of tax amount	22,206	(4,951)	56,722	(23,936)
Unrealized (losses) gains on derivatives used for cash flow hedges	(3,820)	1,689	(5,654)	6,068
Reclassification adjustment for losses included in net income	278	577	501	1,477
Net unrealized (losses) gains on derivatives used for cash flow hedges	(3,542)	2,266	(5,153)	7,545
Tax effect	897	(574)	1,306	(1,912)
Net of tax amount	(2,645)	1,692	(3,847)	5,633
Total other comprehensive income (loss), net of tax	19,561	(3,259)	52,875	(18,303)
Total Comprehensive Income	$ 71,953	$ 41,125	$ 154,399	$ 64,640