Earnings Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Earnings Per Share
Net income (loss) for basic and diluted (loss) income per share	$ 5,302	$ (2,506)
Shares of common stock and common stock equivalents:
Average common shares used in basic computation	32,949,000	33,106,000
Effect of dilutive securities (in shares)	1,181,000
Average common shares used in diluted computation	34,130,000	33,106,000
(Loss) income per share:
Basic (in dollars per share)	$ 0.16	$ (0.08)
Diluted (in dollars per share)	$ 0.16	$ (0.08)
Anti-dilutive equity awards not included in the detailed earnings per share computation
Equity awards not included in the diluted earnings per share computation	0.2	0