Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Statement of Comprehensive Income [Abstract]
Net income	$ 40,979	$ 39,092	$ 117,251	$ 121,566
Other comprehensive income (loss):
Change in unrealized gains on securities	0	0	0	(26)
Reclassification for amounts recognized in investment and other gains	0	0	0	(10,038)
Increase (decrease) in fair value of cash flow hedge	(401)	290	(2,774)	515
Less: reclassification adjustment for amounts recognized in net income	(27)	695	326	2,129
Total other comprehensive income (loss)	374	405	3,100	(8,450)
Comprehensive income	$ 41,353	$ 39,497	$ 120,351	$ 113,116