Earnings Per Share (Schedule of Earnings Per Share, Basic and Diluted) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Numerator
Net income	$ 144,473	$ 113,977	$ 445,637	$ 333,538
Denominator
Weighted average common shares outstanding - basic and diluted:	32,196,589	33,760,940	32,850,647	33,688,531
Weighted average common shares outstanding - basic	32,196,589	33,760,940	32,850,647	33,688,531
Dilutive effect of restricted stock units	373,746	710,104	391,117	731,632
Weighted average common shares outstanding - diluted	32,570,335	34,471,044	33,241,764	34,420,163
Earnings per share:
Basic	$ 4.49	$ 3.38	$ 13.57	$ 9.90
Diluted	$ 4.44	$ 3.31	$ 13.41	$ 9.69