Earnings Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Earnings Per Share Reconciliation [Abstract]
Earnings from continuing operations	$ 10,570	$ 9,298	$ 19,465	$ 15,820
Weighted-average shares outstanding for basic earnings per share (in shares)	64,541,000	64,285,000	64,498,000	64,217,000
Common equivalent shares:
Effect of stock-based compensation awards (in shares)	930,000	922,000	906,000	957,000
Weighted-average shares outstanding assuming dilution (in shares)	65,471,000	65,207,000	65,404,000	65,174,000
Basic earnings per share from continuing operations (in dollars per share)	$ 0.16	$ 0.14	$ 0.30	$ 0.25
Diluted earnings per share from continuing operations (in dollars per share)	$ 0.16	$ 0.14	$ 0.30	$ 0.24
Anti-dilutive securities excluded from computation of earnings per share (in shares)			0	13,000