Fair Value Measurements - Narrative (Details) - USD ($)	Sep. 30, 2021	Mar. 31, 2021	Feb. 17, 2021	Feb. 09, 2021
$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%
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	$ 590,300,000
Fair value of notes	607,200,000
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	$ 700,000,000
Stated interest rate (as a percent)	4.75%	4.75%
Debt amount	$ 692,300,000
Fair value of notes	$ 727,900,000