Earnings Per Share (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended
Mar. 31, 2013	Mar. 31, 2012
Numerator:
Income from continuing operations after income tax expense	$ 18,283	$ 18,767
Basic
Weighted average common shares outstanding	49,417	49,103
Diluted
Stock options (1)	25
Restricted stock awards (1)	342	310
Contingent shares (2)	52	118
Diluted weighted average common shares outstanding	49,836	49,531
Basic earnings per share from continuing operations	$ 0.37	$ 0.38
Diluted earnings per share from continuing operations	$ 0.37	$ 0.38

Incremental common shares attributable to restricted stock awards.

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Amount of income (loss) from continuing operations attributable to the parent. Also defined as revenue less expenses and taxes from ongoing operations before extraordinary items but after deduction of those portions of income or loss from continuing operations that are allocable to noncontrolling interests.

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