Earnings Per Share - Computation of Basic and Diluted Earnings Per Share for Continuing Operations (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Numerator:
Income from continuing operations	$ 8,613	$ 21,479	$ 58,829	$ 58,341
Basic
Weighted average common shares outstanding (in shares)	52,874,000	54,142,000	53,119,000	54,356,000
Diluted
Stock options (in shares)	676,000	760,000	733,000	869,000
Restricted stock awards (in shares)	182,000	146,000	220,000	222,000
Contingent shares (in shares)	37,000	68,000	37,000	68,000
Diluted weighted average common shares outstanding (in shares)	53,769,000	55,116,000	54,109,000	55,515,000
Basic earnings per share from continuing operations (in dollars per share)	$ 0.16	$ 0.40	$ 1.11	$ 1.07
Diluted earnings per share from continuing operations (in dollars per share)	$ 0.16	$ 0.39	$ 1.09	$ 1.05
Share-based payment arrangement (in shares)
Dilutive Securities Included And Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Share based awards excluded from the calculation of diluted earnings per share (in shares)	0	400,000	5,000	400,000
Performance shares (in shares)
Dilutive Securities Included And Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Share based awards excluded from the calculation of diluted earnings per share (in shares)	447,000	324,000	447,000	324,000