Fair Value Measurements - Narrative (Details) - USD ($)	Mar. 31, 2021	Feb. 17, 2021	Feb. 09, 2021	Dec. 31, 2020
$600 Million 4.50% Senior Notes [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Face amount	$ 600,000,000.0
Senior Notes [Member] | $400 Million 5% Senior Notes [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Face amount		$ 400,000,000	$ 400,000,000
Stated interest rate (as a percent)	5.00%	5.00%	5.00%
Debt amount				$ 397,699,000
Senior Notes [Member] | $600 Million 4.50% Senior Notes [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Face amount	$ 600,000,000	$ 600,000,000.0
Stated interest rate (as a percent)	4.50%	4.50%
Debt amount	$ 589,832,000
Fair value of notes	601,000,000
Senior Notes [Member] | $700 Million 4.75% Senior Note [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Face amount	$ 700,000,000
Stated interest rate (as a percent)	4.75%
Debt amount	$ 691,761,000			$ 691,491,000
Fair value of notes	$ 714,000,000