Earnings Per Share - Computation of Basic and Diluted Earnings Per Share for Continuing Operations (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Numerator:
Income from continuing operations	$ 21,695	$ 20,096	$ 80,524	$ 78,437
Basic
Weighted average common shares outstanding (in shares)	52,425	54,403	52,885	54,372
Diluted
Stock options (in shares)	609	738	692	825
Restricted stock units and awards (in shares)	155	135	182	192
Contingent shares (in shares)	37	84	37	84
Diluted weighted average common shares outstanding (in shares)	53,226	55,360	53,796	55,473
Basic earnings per share from continuing operations (in dollars per share)	$ 0.41	$ 0.37	$ 1.52	$ 1.44
Diluted earnings per share from continuing operations (in dollars per share)	$ 0.41	$ 0.36	$ 1.50	$ 1.41
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)	44	274	106	240
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	324	447	324