Condensed Consolidated Statements of Comprehensive Income (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Statement of Comprehensive Income [Abstract]
Net Income	$ 36,396	$ 108,667
Other Comprehensive Income (Loss):
Net unrealized gain on investments, net of taxes	298	18
Net unrealized gain (loss) on derivatives	389	(4,431)
Reclassification adjustment of derivatives and designated hedges into net income	139	371
Retirement liability adjustment	377	377
Total	1,203	(3,665)
Comprehensive Income	37,599	105,002
Comprehensive Income Attributable to Noncontrolling Interests	(5,570)	(1,593)
Comprehensive Income Adjusted for Noncontrolling Interests	$ 32,029	$ 103,409