Net Income (Loss) Per Share and Stockholders' Equity Net Income (Loss) Per Share and Stockholders' Equity, Anti-Dilution Table (Details) - shares shares in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total excluded	52	50	941
Non-vested common shares, restricted stock units and performance shares
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total excluded	52	50	302
Warrants
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total excluded	0	0	639