Earnings Per Share (Details) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended
Mar. 31, 2012	Mar. 31, 2011
Earnings Per Share
Net Income	$ 5,458	$ 9,549
Shares of common stock and common stock equivalents:
Weighted average shares - basic	39,112,000	41,435,000
Effect of dilutive securities (in shares)	1,191,000	745,000
Weighted average shares-diluted	40,303,000	42,180,000
Earnings per share:
Basic (in dollars per share)	$ 0.14	$ 0.23
Diluted (in dollars per share)	$ 0.14	$ 0.23
Anti-dilutive equity awards not included in the detailed earnings per share computation
Equity awards not included in the detailed earnings per share computation	430,000	568,000

Securities (including those issuable pursuant to contingent stock agreements) that could potentially dilute basic earnings per share (EPS) or earnings per unit (EPU) in the future that were not included in the computation of diluted EPS or EPU because to do so would increase EPS or EPU amounts or decrease loss per share or unit amounts for the period presented.

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