Earnings (Losses) Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Net income (loss) (numerator):
Income (loss) from continuing operations, net of tax	$ (161,090)	$ (250,879)	$ (41,890)	$ 124,362	$ (886,401)	$ 102,430	$ 65,729	$ 48,977	$ (329,497)	$ (669,265)	$ 158,341
Less: Net (income) loss attributable to noncontrolling interest	(834)	320	44	89	(202)	(387)	(253)	(573)	(381)	(1,415)	(7,180)
Less: loss on redemption of subsidiary preferred stock										(1,688)
Less: (earnings) losses allocated to unvested shareholders									7,820	10,595	(1,277)
Adjusted income (loss) from continuing operations, net of tax									(322,058)	(661,773)	149,884
Income (loss) from discontinued operations, net of tax	$ (1,730)	$ (45,275)	$ 5,025	$ (817)	$ (4,467)	$ 4,005	$ (1,032)	$ 1,515	$ (42,797)	$ 21	$ (11,179)
Earnings (losses) per share:
Basic from continuing operations (in dollars per share)	$ (0.57)	$ (0.86)	$ (0.14)	$ 0.43	$ (3.06)	$ 0.34	$ 0.21	$ 0.16	$ (1.14)	$ (2.28)	$ 0.51
Basic from discontinued operations (in dollars per share)	(0.01)	(0.16)	0.01		(0.02)	0.02		0.01	(0.15)		(0.04)
Total Basic (in dollars per share)	(0.58)	(1.02)	(0.13)	0.43	(3.08)	0.36	0.21	0.17	(1.29)	(2.28)	0.47
Diluted from continuing operations (in dollars per share)	(0.57)	(0.86)	(0.14)	0.43	(3.06)	0.34	0.21	0.16	(1.14)	(2.28)	0.51
Diluted from discontinued operations (in dollars per share)	(0.01)	(0.16)	0.01	(0.01)	(0.02)	0.01			(0.15)		(0.04)
Total Diluted (in dollars per share)	$ (0.58)	$ (1.02)	$ (0.13)	$ 0.42	$ (3.08)	$ 0.35	$ 0.21	$ 0.16	$ (1.29)	$ (2.28)	$ 0.47
Shares (denominator):
Weighted-average number of shares outstanding - basic									282,982	290,694	294,182
Add: dilutive effect of potential common shares											2,410
Weighted-average number of diluted shares outstanding									282,982	290,694	296,592