Earnings Per Share (Details) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Earnings Per Share Reconciliation [Abstract]
Earnings from continuing operations	$ 9,298	$ 6,915	$ 15,820	$ 15,416
Weighted-average shares outstanding for basic earnings per share (in shares)	64,285,000	64,050,000	64,217,000	63,931,000
Common equivalent shares:
Effect of stock-based compensation awards (in shares)	922,000	809,000	957,000	761,000
Weighted-average shares outstanding assuming dilution (in shares)	65,207,000	64,859,000	65,174,000	64,692,000
Basic earnings per share from continuing operations (in dollars per share)	$ 0.14	$ 0.11	$ 0.25	$ 0.24
Diluted earnings per share from continuing operations (in dollars per share)	$ 0.14	$ 0.11	$ 0.24	$ 0.24
Anti-dilutive securities excluded from computation of earnings per share (in shares)			13,000	13,000