CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (Unaudited) - USD ($)	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Net income	$ 93,960,000	$ 83,510,000
Other comprehensive income (loss), net of tax:
Change in fair value on available-for-sale securities, net of tax	36,379,000	(33,483,000)
Change in fair value of cash flow hedges, net of tax	(523,000)	1,720,000
Amortization of net unrealized losses (gains) on securities transferred from available-for-sale to held-to-maturity, net of tax	29,000	(58,000)
Gain on cash flow hedges reclassified from other comprehensive income into net income, net of tax	(256,000)	(141,000)
Net loss (gain) on sale of investment securities reclassified from other comprehensive income into net income, net of tax	1,448,000	(22,000)
Total other comprehensive income (loss), net of tax	37,077,000	(31,984,000)
Total comprehensive income	$ 131,037,000	$ 51,526,000