Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Earnings Per Share [Abstract]
Discontinued Operation, Income (Loss) from Discontinued Operation, Net of Tax, Per Basic Share	$ 0.00	$ 0.00	$ 0.00	$ 0.00
Net Income (Loss) Attributable to Parent [Abstract]
Net income attributable to common stockholders	$ 52,595	$ 25,922	$ 113,970	$ 67,024
After tax interest on convertible debt	12	13	25	25
Net income — diluted	$ 52,607	$ 25,935	$ 113,995	$ 67,049
Weighted average shares (denominator):
Weighted average shares — basic	(202,466)	(212,390)	(202,966)	(212,613)
Stock options	4,159	3,478	4,134	3,859
Convertible debt	121	121	121	121
Weighted average shares — diluted	206,746	215,989	207,221	216,593
Net income attributable to common stockholders, basic	$ 0.26	$ 0.12	$ 0.56	$ 0.32
Net income attributable to common stockholders, diluted	$ 0.25	$ 0.12	$ 0.55	$ 0.31
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount		1,700	1,000	1,900