Consolidated Statements of Comprehensive Income (Loss) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Statement of Comprehensive Income [Abstract]
Net income (loss), including noncontrolling interests	$ (376,980)	$ 195,550	$ 113,049
Other comprehensive loss, net of tax:
Unrealized loss on hedges arising during the period	(25,259)	(37,364)	(16,847)
Reclassification adjustments for loss included in net income (loss)	13,659	3,365	1,476
Reclassification adjustments for loss from derivatives de-designated as cash flow hedges included in net income	18,014	0	0
Income taxes on unrealized loss on hedges	(2,214)	11,899	5,380
Unrealized gain (loss) on hedges, net of tax	4,200	(22,100)	(9,991)
Foreign currency translation gain (loss)	(12,849)	(19,464)	4,970
Other comprehensive loss, net of tax	(8,649)	(41,564)	(5,021)
Comprehensive income (loss)	(385,629)	153,986	108,028
Less comprehensive income applicable to noncontrolling interests	0	(503)	(3,127)
Comprehensive income (loss) applicable to common shareholders	$ (385,629)	$ 153,483	$ 104,901