Guarantor Subsidiaries (Consolidating Statement of Changes In Equity) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Jan. 01, 2020
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	$ 803,000
Issuance of treasury stock	(500)	$ 0
Purchase of treasury stock	(140,600)	(13,300)
Amounts related to share-based compensation	(5,600)	(4,100)
Share-based compensation expense	2,800	2,600
Cumulative effect of a change in accounting principle			$ 1,100
Net income	89,300	5,300
Ending balance	746,800
Common Stock
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	500	500
Issuance of common stock	0	0
Ending balance	500	500
Treasury Stock
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	(1,099,800)	(940,300)
Issuance of treasury stock	5,200	5,600
Purchase of treasury stock	(140,600)	(13,300)
Ending balance	(1,235,200)	(948,000)
APIC
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	538,700	539,000
Issuance of treasury stock	(5,700)	(5,600)
Amounts related to share-based compensation	(5,600)	(4,100)
Share-based compensation expense	2,800	2,600
Ending balance	530,200	531,900
Retained Earnings
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	1,362,900	1,208,100
Cumulative effect of a change in accounting principle			1,100
Net income	89,300	5,300
Ending balance	1,453,300	1,213,400
AOCI
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	700	0
Other comprehensive income (loss)	(2,700)	0
Ending balance	(2,000)	0
Eliminations
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	(2,735,700)
Net income	(89,200)	(5,100)
Ending balance	(2,824,900)
Eliminations | Common Stock
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	(100)	(100)
Ending balance	(100)	(100)
Eliminations | Treasury Stock
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	0	0
Ending balance	0	0
Eliminations | APIC
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	(1,368,400)	(1,368,400)
Ending balance	(1,368,400)	(1,368,400)
Eliminations | Retained Earnings
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	(1,367,200)	(1,212,900)
Net income	(89,200)	(5,100)
Ending balance	(1,456,400)	(1,218,000)
Eliminations | AOCI
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	0	0
Ending balance	0	0
Parent Company | Reportable Legal Entities
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	2,591,900
Net income	89,300	5,300
Ending balance	2,540,100
Parent Company | Reportable Legal Entities | Common Stock
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	500	500
Ending balance	500	500
Parent Company | Reportable Legal Entities | Treasury Stock
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	(1,099,800)	(940,300)
Issuance of treasury stock	5,200	5,600
Purchase of treasury stock	(140,600)	(13,300)
Ending balance	(1,235,200)	(948,000)
Parent Company | Reportable Legal Entities | APIC
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	1,188,800	1,195,100
Issuance of treasury stock	(5,700)	(5,600)
Ending balance	1,183,100	1,189,500
Parent Company | Reportable Legal Entities | Retained Earnings
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	2,502,400	2,181,800
Net income	89,300	5,300
Ending balance	2,591,700	2,187,100
Parent Company | Reportable Legal Entities | AOCI
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	0	0
Ending balance	0	0
Issuer | Reportable Legal Entities
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	741,400
Net income	89,300	5,300
Ending balance	826,300
Issuer | Reportable Legal Entities | Common Stock
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	0	0
Ending balance	0	0
Issuer | Reportable Legal Entities | Treasury Stock
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	0	0
Ending balance	0	0
Issuer | Reportable Legal Entities | APIC
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	578,800	572,800
Amounts related to share-based compensation	(5,600)	(4,100)
Share-based compensation expense	2,800	2,600
Ending balance	576,000	571,300
Issuer | Reportable Legal Entities | Retained Earnings
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	161,900	172,900
Cumulative effect of a change in accounting principle			$ 1,100
Net income	89,300	5,300
Ending balance	252,300	178,200
Issuer | Reportable Legal Entities | AOCI
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	700	0
Other comprehensive income (loss)	(2,700)	0
Ending balance	(2,000)	0
Guarantor Subsidiaries | Reportable Legal Entities
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	51,100
Net income	(100)	(200)
Ending balance	51,000
Guarantor Subsidiaries | Reportable Legal Entities | Common Stock
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	100	100
Ending balance	100	100
Guarantor Subsidiaries | Reportable Legal Entities | Treasury Stock
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	0	0
Ending balance	0	0
Guarantor Subsidiaries | Reportable Legal Entities | APIC
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	52,000	52,000
Ending balance	52,000	52,000
Guarantor Subsidiaries | Reportable Legal Entities | Retained Earnings
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	(1,000)	(500)
Net income	(100)	(200)
Ending balance	(1,100)	(700)
Guarantor Subsidiaries | Reportable Legal Entities | AOCI
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	0	0
Ending balance	0	0
Non-Guarantor Subsidiaries | Reportable Legal Entities
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	154,300
Net income	0	0
Ending balance	154,300
Non-Guarantor Subsidiaries | Reportable Legal Entities | Common Stock
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	0	0
Ending balance	0	0
Non-Guarantor Subsidiaries | Reportable Legal Entities | Treasury Stock
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	0	0
Ending balance	0	0
Non-Guarantor Subsidiaries | Reportable Legal Entities | APIC
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	87,500	87,500
Ending balance	87,500	87,500
Non-Guarantor Subsidiaries | Reportable Legal Entities | Retained Earnings
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	66,800	66,800
Ending balance	66,800	66,800
Non-Guarantor Subsidiaries | Reportable Legal Entities | AOCI
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	0	0
Ending balance	$ 0	$ 0