Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Net Income (Loss)
Income (loss) from continuing operations									$ (170,928)	$ 23,991	$ 24,441
Income (loss) from discontinued operations									0	0	(11,071)
Net income (loss)	$ 2,543	$ (170,914)	$ (4,172)	$ 1,615	$ 10,089	$ 6,420	$ 5,637	$ 1,845	$ (170,928)	$ 23,991	$ 13,370
Basic EPS
Weighted-average common shares outstanding (in shares)									61,643	62,444	62,503
Continuing operations (in dollars per share)									$ (2.77)	$ 0.38	$ 0.39
Discontinued operations (in dollars per share)									0.00	0.00	(0.18)
Basic earnings (loss) per common share (in dollars per share)	$ 0.04	$ (2.77)	$ (0.07)	$ 0.03	$ 0.16	$ 0.10	$ 0.09	$ 0.03	$ (2.77)	$ 0.38	$ 0.21
Diluted EPS
Shares used in diluted earnings per share computations (in shares)									61,643	62,658	62,812
Continuing operations (in dollars per share)									$ (2.77)	$ 0.38	$ 0.39
Discontinued operations (in dollars per share)									0.00	0.00	(0.18)
Diluted earnings (loss) per common share (in dollars per share)	$ 0.04	$ (2.77)	$ (0.07)	$ 0.03	$ 0.16	$ 0.10	$ 0.09	$ 0.03	$ (2.77)	$ 0.38	$ 0.21
Computation of Shares Used in Earnings Per Share Computations
Weighted-average common shares outstanding (in shares)									61,643	62,444	62,503
Weighted-average common equivalent shares - dilutive effect of stock options and awards (in shares)									0	214	309
Shares used in diluted earnings per share computations (in shares)									61,643	62,658	62,812