Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014	Dec. 31, 2014
Basic EPS
Net income (loss)	$ (4,172)	$ 5,637	$ (2,558)	$ 7,482	$ 23,991
Weighted-average common shares outstanding used in earnings per share computations	61,843	62,734	61,858	62,711
Basic earnings per common share	$ (0.07)	$ 0.09	$ (0.04)	$ 0.12
Diluted EPS
Net income (loss)	$ (4,172)	$ 5,637	$ (2,558)	$ 7,482	$ 23,991
Shares used in diluted earnings per share computations	61,843	62,987	61,858	62,975
Diluted earnings per common share	$ (0.07)	$ 0.09	$ (0.04)	$ 0.12
Computation of Shares Used in Earnings Per Share Computations
Weighted-average common shares outstanding	61,843	62,734	61,858	62,711
Weighted-average common equivalent shares - dilutive effect of stock options and awards		253		264
Shares used in diluted earnings per share computations	61,843	62,987	61,858	62,975