Condensed Consolidated Statements of Comprehensive Income (Unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Statement of Comprehensive Income [Abstract]
Net Income	$ 61,337	$ 45,188	$ 207,655	$ 132,196
Other Comprehensive Income (Loss):
Net unrealized gain (loss) on investments, net of taxes	197	(396)	295	(320)
Realized (loss) gain on derivatives	(2,084)	0	(2,084)	5,007
Net unrealized gain (loss) on derivatives	3,556	(3,423)	(5,015)	(3,042)
Amortization of derivatives and designated hedges	462	(28)	1,193	681
Retirement liability adjustment	251	361	1,004	1,081
Total	2,382	(3,486)	(4,607)	3,407
Comprehensive Income	63,719	41,702	203,048	135,603
Comprehensive Income Attributable to Noncontrolling Interests	(9,436)	(1,787)	(12,864)	(5,119)
Comprehensive Income Adjusted for Noncontrolling Interests	$ 54,283	$ 39,915	$ 190,184	$ 130,484