Long-Term Debt and Other Borrowing Arrangements - Carrying Values of Long-Term Debt and Other Borrowing Arrangements (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019	Mar. 31, 2018	Sep. 30, 2017	Jul. 31, 2017	Oct. 31, 2016
Debt Instrument [Line Items]
Total senior subordinated notes	$ 1,590,810	$ 1,459,380
Less unamortized debt issuance costs	(17,084)	(19,896)
Long-term debt	1,573,726	1,439,484
Revolving credit agreement due 2022
Debt Instrument [Line Items]
Revolving credit agreement due 2022	0	0
3.875% Senior Subordinated Notes Due 2028
Debt Instrument [Line Items]
Total senior subordinated notes	428,295	392,910
3.375% Senior Subordinated Notes Due 2027
Debt Instrument [Line Items]
Total senior subordinated notes	550,665	505,170
4.125% Senior Subordinated Notes Due 2026
Debt Instrument [Line Items]
Total senior subordinated notes	244,740	224,520
2.875% Senior Subordinated Notes Due 2025
Debt Instrument [Line Items]
Total senior subordinated notes	$ 367,110	$ 336,780
Senior Subordinated Notes | 3.875% Senior Subordinated Notes Due 2028
Debt Instrument [Line Items]
Senior subordinated notes interest rate			3.875%
Senior Subordinated Notes | 3.375% Senior Subordinated Notes Due 2027
Debt Instrument [Line Items]
Senior subordinated notes interest rate					3.375%
Senior Subordinated Notes | 4.125% Senior Subordinated Notes Due 2026
Debt Instrument [Line Items]
Senior subordinated notes interest rate						4.125%
Senior Subordinated Notes | 2.875% Senior Subordinated Notes Due 2025
Debt Instrument [Line Items]
Senior subordinated notes interest rate				2.875%