Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Numerator
Basic - income (loss) from continuing operations	$ (40,712)	$ (90,828)	$ 79,009
Assumed conversions of Convertible Notes due 2017	0	0	5,091
Diluted - adjusted income (loss) from continuing operations	$ (40,712)	$ (90,828)	$ 84,100
Denominator
Basic - weighted average common shares outstanding (in shares)	83,697	82,722	82,999
Dilutive effect of stock options and restricted stock awards (in shares)	0	0	1,733
Diluted weighted average number of common shares outstanding (in shares)	83,697	82,722	100,414
Income (loss) from continuing operations (in dollars per share)	$ (0.49)	$ (1.10)	$ 0.95
Income (loss) from continuing operations (in dollars per share)	$ (0.49)	$ (1.10)	$ 0.84
Convertible Notes due 2017 [Member] | Convertible debt [Member]
Denominator
Dilutive effect of the convertible notes (in shares)	0	0	15,682
Convertible Notes due 2021 [Member] | Convertible debt [Member]
Denominator
Dilutive effect of the convertible notes (in shares)	0	0	0