Share-Based Compensation - Narrative (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares authorized under Stock Incentive Plan	30,600,000
Number of shares available for grant under Stock Incentive Plan	3,500,000
Share-based compensation expense	$ 25,057	$ 23,893	$ 22,508
Tax benefit from share-based compensation	6,000	$ 5,600	$ 8,400
Nonvested awards, total compensation cost not yet recognized	$ 75,000
Nonvested awards, total compensation cost not yet recognized, period for recognition	6 years
Restricted stock granted in period (in shares)	928,324	899,269	946,570
Restricted stock granted in period, weighted average grant date fair value (usd per share)	$ 30.10	$ 28.30	$ 27.20
Restricted stock, vested in period, total fair value	$ 28,400	$ 24,000	$ 23,900
Class B Common Stock Bonus
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award requisite service period	3 years
Restricted stock granted in period (in shares)	498,324
Class B Common Stock Key Employees
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award requisite service period	10 years
Restricted stock granted in period (in shares)	430,000
Subsidiary Stock Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Nonvested awards, total compensation cost not yet recognized	$ 30,000
Nonvested awards, total compensation cost not yet recognized, period for recognition	4 years
Compensation and Related expense	$ 7,900	$ 4,200

Amount of expense for award under share-based payment arrangement. Excludes amount capitalized.

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Amount of cost not yet recognized for nonvested award under share-based payment arrangement.

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Weighted-average period over which cost not yet recognized is expected to be recognized for award under share-based payment arrangement, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days.

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The number of grants made during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan).

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