Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Statement of Comprehensive Income [Abstract]
Net Income	$ 157,870	$ 98,387	$ 92,349
Unrealized holding (losses) gains:
Before tax	(16,294)	12,641	(19,204)
Tax effect	4,342	(5,077)	7,682
Net of tax	(11,952)	7,564	(11,522)
Reclassification of net gains (losses) included in net income:
Before tax	0	(1,876)	1,420
Tax effect	0	771	(568)
Net of tax	0	(1,105)	852
Net unrealized holding (losses) gains	(11,952)	8,669	(12,374)
Derivative Instruments
Before tax	2,786	(4,333)	2,175
Tax effect	(789)	1,746	(883)
Net of tax	1,997	(2,587)	1,292
Net unrealized holding (losses) gains
Before tax	(3,850)	2,988	(2,002)
Tax effect	1,018	(1,196)	563
Net of tax	(2,832)	1,792	(1,439)
Total other comprehensive (loss) income	(12,787)	7,874	(12,521)
Total comprehensive income	$ 145,083	$ 106,261	$ 79,828