Earnings Per Share (Tables)

9 Months Ended

Sep. 30, 2020

Earnings Per Share [Abstract]

Basic and Diluted Earnings Per Share

	Three months ended				Nine months ended
	September 30,				September 30,
	2020		2019		2020		2019
Net income	$	80,244	$	98,582	$	164,807	$	277,742
Shares:
Weighted-average number of common shares outstanding (for basic calculation)		27,973		27,775		27,892		27,730
Dilutive stock awards		481		613		478		538
Weighted-average number of common shares outstanding (for diluted calculation)		28,454		28,388		28,370		28,268
Basic earnings per share	$	2.87	$	3.55	$	5.91	$	10.02
Diluted earnings per share	$	2.82	$	3.47	$	5.81	$	9.83

Stock Awards Excluded from the Calculation of Diluted EPS

	Three months ended				Nine months ended
	September 30,				September 30,
	2020		2019		2020		2019
Stock awards subject to performance conditions		100		84		97		83
Stock awards that were antidilutive		2		17		74		178
Total stock awards excluded from diluted earnings per share		102		101		171		261