Finance Receivables (Changes In Allowance For Credit Losses On Finance Receivables) (Detail) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Sep. 30, 2018	Sep. 24, 2017	Sep. 30, 2018	Sep. 24, 2017	Dec. 31, 2017	Jun. 26, 2016
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Balance, beginning of period	$ 193,930	$ 193,528	$ 192,471	$ 173,343
Provision for credit losses	23,530	29,253	72,462	99,059
Charge-offs	(33,697)	(37,783)	(107,725)	(114,081)
Recoveries	9,684	10,584	36,239	37,261
Balance, end of period	193,447	195,582	193,447	195,582
Current unpaid balance - off-balance sheet retail motorcycle finance receivables	93,147	165,169	93,147	165,169	$ 146,425
Current unpaid balance - on-balance sheet retail motorcycle finance receivables	6,360,907	6,185,144	6,360,907	6,185,144	$ 5,993,185
Variable Interest Entity, Not Primary Beneficiary
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Principal balance of finance receivable						$ 301,800
Retail
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Balance, beginning of period	187,502	185,899	186,254	166,810
Provision for credit losses	23,629	30,964	72,350	99,674
Charge-offs	(33,689)	(37,783)	(107,717)	(114,081)
Recoveries	9,684	10,584	36,239	37,261
Balance, end of period	187,126	189,664	187,126	189,664
Wholesale
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Balance, beginning of period	6,428	7,629	6,217	6,533
Provision for credit losses	(99)	(1,711)	112	(615)
Charge-offs	(8)	0	(8)	0
Recoveries	0	0	0	0
Balance, end of period	$ 6,321	$ 5,918	$ 6,321	$ 5,918

Principal amount of transferred financial assets in which the transferor has continuing involvement with the assets underlying the transaction. Continuing involvement includes, but is not limited to, servicing, recourse, and restrictions on transferor's interests in transferred financial assets.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 860
-SubTopic 20
-Section 50
-Paragraph 4
-Subparagraph (a)(1)
-URI http://asc.fasb.org/extlink&oid=82924980&loc=d3e107314-111719

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- Definition

Amount of transferred financial assets in which the transferor has continuing involvement with the assets underlying the transaction that have been derecognized. Continuing involvement includes, but is not limited to, servicing, recourse, and restrictions on transferor's interests in transferred financial assets.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 860
-SubTopic 20
-Section 50
-Paragraph 4
-Subparagraph (a)(2)
-URI http://asc.fasb.org/extlink&oid=82924980&loc=d3e107314-111719

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- Definition

A valuation allowance for financing receivables that are expected to be uncollectible.

+ References

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- Definition

Amount of recovery of financing receivables doubtful of collection that were previously charged off.

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- Definition

A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

+ References

No definition available.

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Amount of direct write-downs of financing receivables charged against the allowance.

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- Definition

Amount of expense related loan transactions, lease transactions, credit loss from transactions other than loan and lease transactions, and other loss based on assessment of uncollectability from the counterparty to reduce the account to their net realizable value.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 11B
-Subparagraph (c)(2)
-URI http://asc.fasb.org/extlink&oid=84173941&loc=SL6953423-111524

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 225
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-04.11)
-URI http://asc.fasb.org/extlink&oid=6879574&loc=d3e536633-122882

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
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-Section 45
-Paragraph 28
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=98514028&loc=d3e3602-108585

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- Definition

Amount of derecognized financial assets from transactions which comprise an initial transfer and an agreement entered into in contemplation of the initial transfer resulting in retention of substantially all of the exposure to the economic return throughout the term of the transaction, at the date of derecognition.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 860
-SubTopic 20
-Section 50
-Paragraph 4D
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=82924980&loc=SL51823488-111719

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