Earnings Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Class A common stock
Income available to stockholders (Basic EPS:)
Allocated net income (numerator)	$ 79,491	$ 78,382	$ 147,548	$ 151,346
Weighted shares (denominator) (in shares)	46,188,845	46,188,289	46,188,803	46,188,573
Per-share amount (in dollars per share)	$ 1.72	$ 1.70	$ 3.19	$ 3.28
Dilutive effect of stock-based awards
Allocated net income (numerator)	$ 0	$ 0	$ 0	$ 0
Weighted shares (denominator) (in shares)	6,494	13,281	8,718	19,790
Assumed conversion of Class B shares
Allocated net income (numerator)	$ 656	$ 647	$ 1,218	$ 1,249
Weighted shares (denominator) (in shares)	6,100,800	6,100,800	6,100,800	6,100,800
Income available to stockholders on equivalent shares (Diluted EPS:)
Allocated net income (numerator)	$ 80,147	$ 79,029	$ 148,766	$ 152,595
Weighted shares (denominator) (in shares)	52,296,139	52,302,370	52,298,321	52,309,163
Per-share amount (in dollars per share)	$ 1.53	$ 1.51	$ 2.84	$ 2.92
Class B common stock
Income available to stockholders (Basic EPS:)
Allocated net income (numerator)	$ 656	$ 647	$ 1,218	$ 1,249
Weighted shares (denominator) (in shares)	2,542	2,542	2,542	2,542
Per-share amount (in dollars per share)	$ 258	$ 255	$ 479	$ 491
Income available to stockholders on equivalent shares (Diluted EPS:)
Allocated net income (numerator)	$ 656	$ 647	$ 1,218	$ 1,249
Weighted shares (denominator) (in shares)	2,542	2,542	2,542	2,542
Per-share amount (in dollars per share)	$ 258	$ 255	$ 479	$ 491