Supplemental Consolidating Data (Balance Sheet) (Detail) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017	Sep. 24, 2017
Current assets:
Cash and cash equivalents	$ 926,992	$ 687,521	$ 683,134
Marketable securities	10,011	0	0
Accounts receivable, net	332,309	329,986	343,124
Finance receivables, net	2,116,386	2,105,662	2,058,168
Inventories	516,247	538,202	469,091
Restricted cash	36,471	47,518	52,209
Other current assets	151,042	175,853	182,416
Total current assets	4,089,458	3,884,742	3,788,142
Finance receivables, net	5,187,176	4,859,424	5,042,857
Property, plant and equipment, net	884,960	967,781	934,615
Prepaid pension costs	140,763	19,816	0
Goodwill	55,318	55,947	55,898
Deferred income taxes	63,559	109,073	180,575
Other long-term assets	82,566	75,889	86,272
Total assets	10,503,800	9,972,672	10,088,359
Current liabilities:
Accounts payable	310,967	227,597	277,117
Accrued liabilities	564,832	529,822	573,958
Short-term debt	1,373,859	1,273,482	834,875
Current portion of long-term debt, net	1,526,156	1,127,269	1,530,401
Total current liabilities	3,775,814	3,158,170	3,216,351
Long-term debt, net	4,196,517	4,587,258	4,607,791
Pension liability	54,138	54,606	52,471
Postretirement healthcare benefits	112,798	118,753	162,925
Other long-term liabilities	211,561	209,608	192,001
Shareholders’ equity	2,152,972	1,844,277	1,856,820
Total liabilities and shareholders' equity	10,503,800	9,972,672	10,088,359
Reportable Legal Entities | Motorcycles And Related Products Operations
Current assets:
Cash and cash equivalents	576,670	338,186	311,029
Marketable securities	10,011
Accounts receivable, net	640,416	483,709	690,152
Finance receivables, net	0	0	0
Inventories	516,247	538,202	469,091
Restricted cash	0	0	0
Other current assets	106,259	132,999	146,012
Total current assets	1,849,603	1,493,096	1,616,284
Finance receivables, net	0	0	0
Property, plant and equipment, net	833,279	922,280	892,260
Prepaid pension costs	140,763	19,816
Goodwill	55,318	55,947	55,898
Deferred income taxes	25,780	66,877	109,116
Other long-term assets	151,815	138,344	149,257
Total assets	3,056,558	2,696,360	2,822,815
Current liabilities:
Accounts payable	291,395	214,263	257,205
Accrued liabilities	483,964	444,028	479,753
Short-term debt	0	0	0
Current portion of long-term debt, net	0	0	0
Total current liabilities	775,359	658,291	736,958
Long-term debt, net	742,458	741,961	741,797
Pension liability	54,138	54,606	52,471
Postretirement healthcare benefits	112,798	118,753	162,925
Other long-term liabilities	170,464	171,200	154,696
Shareholders’ equity	1,201,341	951,549	973,968
Total liabilities and shareholders' equity	3,056,558	2,696,360	2,822,815
Reportable Legal Entities | Financial Services Operations
Current assets:
Cash and cash equivalents	350,322	349,335	372,105
Marketable securities	0
Accounts receivable, net	0	0	0
Finance receivables, net	2,116,386	2,105,662	2,058,168
Inventories	0	0	0
Restricted cash	36,471	47,518	52,209
Other current assets	44,783	48,521	46,956
Total current assets	2,547,962	2,551,036	2,529,438
Finance receivables, net	5,187,176	4,859,424	5,042,857
Property, plant and equipment, net	51,681	45,501	42,355
Prepaid pension costs	0	0
Goodwill	0	0	0
Deferred income taxes	39,203	43,515	73,424
Other long-term assets	19,799	23,593	22,499
Total assets	7,845,821	7,523,069	7,710,573
Current liabilities:
Accounts payable	327,679	167,057	366,940
Accrued liabilities	80,427	90,942	104,814
Short-term debt	1,373,859	1,273,482	834,875
Current portion of long-term debt, net	1,526,156	1,127,269	1,530,401
Total current liabilities	3,308,121	2,658,750	2,837,030
Long-term debt, net	3,454,059	3,845,297	3,865,994
Pension liability	0	0	0
Postretirement healthcare benefits	0	0	0
Other long-term liabilities	38,003	35,503	34,071
Shareholders’ equity	1,045,638	983,519	973,478
Total liabilities and shareholders' equity	7,845,821	7,523,069	7,710,573
Eliminations
Current assets:
Cash and cash equivalents	0	0	0
Marketable securities	0
Accounts receivable, net	(308,107)	(153,723)	(347,028)
Finance receivables, net	0	0	0
Inventories	0	0	0
Restricted cash	0	0	0
Other current assets	0	(5,667)	(10,552)
Total current assets	(308,107)	(159,390)	(357,580)
Finance receivables, net	0	0	0
Property, plant and equipment, net	0	0	0
Prepaid pension costs	0	0
Goodwill	0	0	0
Deferred income taxes	(1,424)	(1,319)	(1,965)
Other long-term assets	(89,048)	(86,048)	(85,484)
Total assets	(398,579)	(246,757)	(445,029)
Current liabilities:
Accounts payable	(308,107)	(153,723)	(347,028)
Accrued liabilities	441	(5,148)	(10,609)
Short-term debt	0	0	0
Current portion of long-term debt, net	0	0	0
Total current liabilities	(307,666)	(158,871)	(357,637)
Long-term debt, net	0	0	0
Pension liability	0	0	0
Postretirement healthcare benefits	0	0	0
Other long-term liabilities	3,094	2,905	3,234
Shareholders’ equity	(94,007)	(90,791)	(90,626)
Total liabilities and shareholders' equity	$ (398,579)	$ (246,757)	$ (445,029)