CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (Unaudited) - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
		Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest		$ 20,732	$ 13,904	$ 88,365	$ 73,939
Other comprehensive income (loss), net of tax
Change in fair value of investments in available-for-sale securities, net of tax		648	0	648	122
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI for Sale of Securities, Net of Tax		0	0	0	557
Total change in unrealized gains (losses) on investments in available-for-sale securities, net of tax	[1]	648	0	648	(435)
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI on Derivatives, Net of Tax		0	0	0	(1,821)
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, Net of Tax	[2]	0	0	0	(1,821)
Total other comprehensive income (loss), net of tax		648	0	648	(2,256)
Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest		21,380	13,904	89,013	71,683
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Noncontrolling Interest		0	(3)	(47)	(3)
Comprehensive income		$ 21,380	$ 13,907	$ 89,060	$ 71,686

[1] Net of tax of $349 and zero for the three months ended September 30, 2017 and 2016, respectively

[2] Net of tax of zero and zero for the three months ended September 30, 2017 and 2016, respectively