Summary of Significant Accounting Policies - Earnings Per Share (Details) - USD ($) shares in Thousands, $ in Thousands		3 Months Ended		9 Months Ended
		Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Numerator (for basic and diluted earnings per share)
Income (loss) from continuing operations		$ 12,522	$ (24,443)	$ 28,898	$ (45,513)
Less income allocated to RSUs		174	0	373	0
Numerator for basic and diluted earnings per share from continuing operations		$ 12,348	$ (24,443)	$ 28,525	$ (45,513)
Denominator
Basic weighted-average shares outstanding		83,230	84,107	83,654	75,213
Effect of dilutive securities:
Stock options held by employees and directors		288	0	306	0
Diluted weighted-average shares outstanding		83,518	84,107	83,960	75,213
Anti-dilutive securities	[1]	0	2,148	0	2,148

[1] (1) Amount outstanding at balance sheet date, before application of the treasury stock method and not weighted for period outstanding