Earnings Per Share (Details) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2022 USD ($) $ / shares shares	Dec. 31, 2021 USD ($) $ / shares shares	Dec. 31, 2020 USD ($) $ / shares shares
Class A common stock
Income available to stockholders (Basic EPS:)
Allocated net income (numerator) | $	$ 296,125	$ 295,421	$ 290,902
Weighted shares (denominator) (in shares) | shares	46,188,916	46,188,806	46,188,659
Per- share amount (in dollars per share) | $ / shares	$ 6.41	$ 6.40	$ 6.30
Dilutive effect of stock-based awards
Allocated net income (numerator) | $	$ 0	$ 0	$ 0
Weighted shares (denominator) (in shares) | shares	8,274	17,696	23,901
Assumed conversion of Class B shares
Allocated net income (numerator) | $	$ 2,444	$ 2,439	$ 2,402
Weighted shares (denominator) (in shares) | shares	6,100,800	6,100,800	6,100,800
Income available to stockholders on equivalent shares (Diluted EPS:)
Allocated net income (numerator) | $	$ 298,569	$ 297,860	$ 293,304
Weighted shares (denominator) (in shares) | shares	52,297,990	52,307,302	52,313,360
Per- share amount (in dollars per share) | $ / shares	$ 5.71	$ 5.69	$ 5.61
Class B common stock
Reconciliation of the numerators and denominators used in the basic and diluted per-share computations
Ratio for converting shares of Class B common stock into shares of Class A common stock	2,400	2,400
Income available to stockholders (Basic EPS:)
Allocated net income (numerator) | $	$ 2,444	$ 2,439	$ 2,402
Weighted shares (denominator) (in shares) | shares	2,542	2,542	2,542
Per- share amount (in dollars per share) | $ / shares	$ 962	$ 959	$ 945
Income available to stockholders on equivalent shares (Diluted EPS:)
Allocated net income (numerator) | $	$ 2,444	$ 2,438	$ 2,401
Weighted shares (denominator) (in shares) | shares	2,542	2,542	2,542
Per- share amount (in dollars per share) | $ / shares	$ 962	$ 959	$ 945