CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Statement of Comprehensive Income [Abstract]
Net income	$ 108,648	$ 109,546	$ 108,080
Other comprehensive income/(loss) before taxes:
Net unrealized gains/(losses) on available-for-sale securities	37,291	(22,831)	(29,980)
Net changes in held-to-maturity securities	(12,677)	(13,415)	(6,067)
Net unrealized (losses)/gains on cash flow hedges	(21,780)	(15,801)	2,938
Other comprehensive income/(loss) before tax	2,834	(52,047)	(33,109)
Income tax (expense)/benefit related to other comprehensive income/(loss)	(596)	10,930	6,953
Other comprehensive income/(loss) net of tax	2,238	(41,117)	(26,156)
Comprehensive income	$ 110,886	$ 68,429	$ 81,924