Supplemental Guarantor Information (Statement Of Cash Flows) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Net cash provided by (used in) operating activities	$ 1,077,545	$ 1,449,747	$ 663,080
Cash flows from investing activities:
Capital expenditures	(58,119)	(59,039)	(32,051)
Investments in unconsolidated entities	(9,515)	(1,000)	(23,037)
Business acquisition	(163,724)	0	0
Other investing activities, net	5,129	18,097	4,846
Net cash provided by (used in) investing activities	(226,229)	(41,942)	(50,242)
Cash flows from financing activities:
Financial Services borrowings (repayments), net	(21,841)	(89,393)	106,183
Payments of Debt Issuance Costs	0	(8,164)	0
Debt issuance costs			0
Repayments of notes payable	(309,985)	(82,775)	(134,747)
Borrowings under revolving credit facility	0	1,566,000	2,720,000
Repayments under revolving credit facility	0	(1,566,000)	(2,720,000)
Stock option exercises	6,399	6,555	27,720
Share repurchases	(274,333)	(294,566)	(910,331)
Payment, Tax Withholding, Share-based Payment Arrangement	11,450	7,910	5,995
Dividends paid	(122,350)	(104,020)	(112,748)
Intercompany activities, net	0	0	0
Net cash provided by (used in) financing activities	(733,560)	(580,273)	(1,029,918)
Net increase (decrease)	117,756	827,532	(417,080)
Cash, cash equivalents, and restricted cash at beginning of period	1,133,700	306,168	723,248
Cash, cash equivalents, and restricted cash at end of period	1,251,456	1,133,700	306,168
Parent Company [Member]
Net cash provided by (used in) operating activities	195,371	494,521	309,760
Cash flows from investing activities:
Capital expenditures	0	0	0
Investments in unconsolidated entities	0	0	0
Business acquisition	0	0	0
Other investing activities, net	0	0	0
Net cash provided by (used in) investing activities	0	0	0
Cash flows from financing activities:
Financial Services borrowings (repayments), net	0	0	0
Payments of Debt Issuance Costs	0	8,164
Debt issuance costs			0
Repayments of notes payable	(280,259)	0	(123,000)
Borrowings under revolving credit facility	0	1,566,000	2,720,000
Repayments under revolving credit facility	0	(1,566,000)	(2,720,000)
Stock option exercises	6,399	6,555	27,720
Share repurchases	(274,333)	(294,566)	(910,331)
Payment, Tax Withholding, Share-based Payment Arrangement	11,450	7,910	5,995
Dividends paid	(122,350)	(104,020)	(112,748)
Intercompany activities, net	486,622	(86,416)	814,594
Net cash provided by (used in) financing activities	(195,371)	(494,521)	(309,760)
Net increase (decrease)	0	0	0
Cash, cash equivalents, and restricted cash at beginning of period	0	0	0
Cash, cash equivalents, and restricted cash at end of period	0	0	0
Guarantor Subsidiaries [Member]
Net cash provided by (used in) operating activities	858,338	791,350	328,163
Cash flows from investing activities:
Capital expenditures	(48,899)	(51,147)	(25,432)
Investments in unconsolidated entities	(8,807)	(1,000)	(23,037)
Business acquisition	(163,724)	0	0
Other investing activities, net	3,337	11,300	5,778
Net cash provided by (used in) investing activities	(218,093)	(40,847)	(42,691)
Cash flows from financing activities:
Financial Services borrowings (repayments), net	0	0	0
Payments of Debt Issuance Costs	0	0
Debt issuance costs			0
Repayments of notes payable	(29,189)	(81,758)	(10,301)
Borrowings under revolving credit facility	0	0	0
Repayments under revolving credit facility	0	0	0
Stock option exercises	0	0	0
Share repurchases	0	0	0
Payment, Tax Withholding, Share-based Payment Arrangement	0	0	0
Dividends paid	0	0	0
Intercompany activities, net	(482,352)	102,821	(728,555)
Net cash provided by (used in) financing activities	(511,541)	21,063	(738,856)
Net increase (decrease)	128,704	771,566	(453,384)
Cash, cash equivalents, and restricted cash at beginning of period	929,367	157,801	611,185
Cash, cash equivalents, and restricted cash at end of period	1,058,071	929,367	157,801
Non-Guarantor Subsidiaries [Member]
Net cash provided by (used in) operating activities	23,836	163,876	25,157
Cash flows from investing activities:
Capital expenditures	(9,220)	(7,892)	(6,619)
Investments in unconsolidated entities	(708)	0	0
Business acquisition	0	0	0
Other investing activities, net	1,792	6,797	(932)
Net cash provided by (used in) investing activities	(8,136)	(1,095)	(7,551)
Cash flows from financing activities:
Financial Services borrowings (repayments), net	(21,841)	(89,393)	106,183
Payments of Debt Issuance Costs	0	0
Debt issuance costs			0
Repayments of notes payable	(537)	(1,017)	(1,446)
Borrowings under revolving credit facility	0	0	0
Repayments under revolving credit facility	0	0	0
Stock option exercises	0	0	0
Share repurchases	0	0	0
Payment, Tax Withholding, Share-based Payment Arrangement	0	0	0
Dividends paid	0	0	0
Intercompany activities, net	(4,270)	(16,405)	(86,039)
Net cash provided by (used in) financing activities	(26,648)	(106,815)	18,698
Net increase (decrease)	(10,948)	55,966	36,304
Cash, cash equivalents, and restricted cash at beginning of period	204,333	148,367	112,063
Cash, cash equivalents, and restricted cash at end of period	193,385	204,333	148,367
Eliminating Entries [Member]
Net cash provided by (used in) operating activities	0	0	0
Cash flows from investing activities:
Capital expenditures	0	0	0
Investments in unconsolidated entities	0	0	0
Business acquisition	0	0	0
Other investing activities, net	0	0	0
Net cash provided by (used in) investing activities	0	0	0
Cash flows from financing activities:
Financial Services borrowings (repayments), net	0	0	0
Payments of Debt Issuance Costs	0	0
Debt issuance costs			0
Repayments of notes payable	0	0	0
Borrowings under revolving credit facility	0	0	0
Repayments under revolving credit facility	0	0	0
Stock option exercises	0	0	0
Share repurchases	0	0	0
Payment, Tax Withholding, Share-based Payment Arrangement	0	0	0
Dividends paid	0	0	0
Intercompany activities, net	0	0	0
Net cash provided by (used in) financing activities	0	0	0
Net increase (decrease)	0	0	0
Cash, cash equivalents, and restricted cash at beginning of period	0	0	0
Cash, cash equivalents, and restricted cash at end of period	$ 0	$ 0	$ 0