CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (UNAUDITED) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Statement of Comprehensive Income [Abstract]
Net income	$ 44,179	$ 37,057	$ 131,228	$ 91,426
Other comprehensive income (loss), net of tax:
Change in unrealized gains (losses) on available-for-sale securities, net of tax	161	134	2,129	54
Change in unrealized gains (losses) on derivative contracts, net of tax	409	1,881	3,189	(1,839)
Other comprehensive income (loss), net of tax	570	2,015	5,318	(1,785)
Total comprehensive income, net of tax	$ 44,749	$ 39,072	$ 136,546	$ 89,641