Condensed Consolidated Statements of Comprehensive Income (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Statement of Comprehensive Income [Abstract]
Net Income	$ 108,667	$ 49,222
Other Comprehensive Loss:
Net unrealized gain on investments, net of taxes	18	79
Net unrealized loss on derivatives	(4,431)	(1,350)
Amortization of loss on derivatives and designated hedges	371	388
Retirement liability adjustment	377	360
Total	(3,665)	(523)
Comprehensive Income	105,002	48,699
Comprehensive Income Attributable to Noncontrolling Interests	(1,593)	(1,575)
Comprehensive Income Adjusted for Noncontrolling Interests	$ 103,409	$ 47,124