Asset-Backed Financing (Assets And Liabilities Of Variable Interest Entities) (Detail) - USD ($) $ in Thousands	Mar. 26, 2017	Dec. 31, 2016	Mar. 27, 2016
Finance receivables
Assets and Associated Liabilities of Transfers Accounted for as Secured Borrowings [Line Items]
Transfers accounts for as secured borrowings, assets, carrying amount	$ 1,231,483	$ 1,059,523	$ 1,589,596
Finance receivables | Asset-backed securitizations | SPEs
Assets and Associated Liabilities of Transfers Accounted for as Secured Borrowings [Line Items]
Transfers accounts for as secured borrowings, assets, carrying amount	772,152	893,804	1,421,332
Finance receivables | Asset-backed U.S. commercial paper conduit facilities | SPEs
Assets and Associated Liabilities of Transfers Accounted for as Secured Borrowings [Line Items]
Transfers accounts for as secured borrowings, assets, carrying amount	304,091	0	0
Finance receivables | Asset-backed Canadian commercial paper conduit facility | Variable Interest Entity, Not Primary Beneficiary
Assets and Associated Liabilities of Transfers Accounted for as Secured Borrowings [Line Items]
Transfers accounts for as secured borrowings, assets, carrying amount	155,240	165,719	168,264
Allowance for credit losses
Assets and Associated Liabilities of Transfers Accounted for as Secured Borrowings [Line Items]
Transfers accounts for as secured borrowings, assets, carrying amount	(35,465)	(29,041)	(38,316)
Allowance for credit losses | Asset-backed securitizations | SPEs
Assets and Associated Liabilities of Transfers Accounted for as Secured Borrowings [Line Items]
Transfers accounts for as secured borrowings, assets, carrying amount	(23,239)	(25,468)	(35,161)
Allowance for credit losses | Asset-backed U.S. commercial paper conduit facilities | SPEs
Assets and Associated Liabilities of Transfers Accounted for as Secured Borrowings [Line Items]
Transfers accounts for as secured borrowings, assets, carrying amount	(9,178)	0	0
Allowance for credit losses | Asset-backed Canadian commercial paper conduit facility | Variable Interest Entity, Not Primary Beneficiary
Assets and Associated Liabilities of Transfers Accounted for as Secured Borrowings [Line Items]
Transfers accounts for as secured borrowings, assets, carrying amount	(3,048)	(3,573)	(3,155)
Restricted cash
Assets and Associated Liabilities of Transfers Accounted for as Secured Borrowings [Line Items]
Transfers accounts for as secured borrowings, assets, carrying amount	90,279	67,147	114,924
Restricted cash | Asset-backed securitizations | SPEs
Assets and Associated Liabilities of Transfers Accounted for as Secured Borrowings [Line Items]
Transfers accounts for as secured borrowings, assets, carrying amount	63,473	57,057	102,594
Restricted cash | Asset-backed U.S. commercial paper conduit facilities | SPEs
Assets and Associated Liabilities of Transfers Accounted for as Secured Borrowings [Line Items]
Transfers accounts for as secured borrowings, assets, carrying amount	15,781	0	0
Restricted cash | Asset-backed Canadian commercial paper conduit facility | Variable Interest Entity, Not Primary Beneficiary
Assets and Associated Liabilities of Transfers Accounted for as Secured Borrowings [Line Items]
Transfers accounts for as secured borrowings, assets, carrying amount	11,025	10,090	12,330
Other assets
Assets and Associated Liabilities of Transfers Accounted for as Secured Borrowings [Line Items]
Transfers accounts for as secured borrowings, assets, carrying amount	3,586	3,207	4,877
Other assets | Asset-backed securitizations | SPEs
Assets and Associated Liabilities of Transfers Accounted for as Secured Borrowings [Line Items]
Transfers accounts for as secured borrowings, assets, carrying amount	2,532	2,452	4,169
Other assets | Asset-backed U.S. commercial paper conduit facilities | SPEs
Assets and Associated Liabilities of Transfers Accounted for as Secured Borrowings [Line Items]
Transfers accounts for as secured borrowings, assets, carrying amount	672	329	302
Other assets | Asset-backed Canadian commercial paper conduit facility | Variable Interest Entity, Not Primary Beneficiary
Assets and Associated Liabilities of Transfers Accounted for as Secured Borrowings [Line Items]
Transfers accounts for as secured borrowings, assets, carrying amount	382	426	406
Total assets
Assets and Associated Liabilities of Transfers Accounted for as Secured Borrowings [Line Items]
Transfers accounts for as secured borrowings, assets, carrying amount	1,289,883	1,100,836	1,671,081
Total assets | Asset-backed securitizations | SPEs
Assets and Associated Liabilities of Transfers Accounted for as Secured Borrowings [Line Items]
Transfers accounts for as secured borrowings, assets, carrying amount	814,918	927,845	1,492,934
Total assets | Asset-backed U.S. commercial paper conduit facilities | SPEs
Assets and Associated Liabilities of Transfers Accounted for as Secured Borrowings [Line Items]
Transfers accounts for as secured borrowings, assets, carrying amount	311,366	329	302
Total assets | Asset-backed Canadian commercial paper conduit facility | Variable Interest Entity, Not Primary Beneficiary
Assets and Associated Liabilities of Transfers Accounted for as Secured Borrowings [Line Items]
Transfers accounts for as secured borrowings, assets, carrying amount	163,599	172,662	177,845
Asset-backed debt
Assets and Associated Liabilities of Transfers Accounted for as Secured Borrowings [Line Items]
Transfers accounts for as secured borrowings, associated liabilities, carrying amount	1,112,592	945,613	1,440,040
Asset-backed debt | Asset-backed securitizations | SPEs
Assets and Associated Liabilities of Transfers Accounted for as Secured Borrowings [Line Items]
Transfers accounts for as secured borrowings, associated liabilities, carrying amount	685,374	796,275	1,286,729
Asset-backed debt | Asset-backed U.S. commercial paper conduit facilities | SPEs
Assets and Associated Liabilities of Transfers Accounted for as Secured Borrowings [Line Items]
Transfers accounts for as secured borrowings, associated liabilities, carrying amount	286,205	0	0
Asset-backed debt | Asset-backed Canadian commercial paper conduit facility | Variable Interest Entity, Not Primary Beneficiary
Assets and Associated Liabilities of Transfers Accounted for as Secured Borrowings [Line Items]
Transfers accounts for as secured borrowings, associated liabilities, carrying amount	$ 141,013	$ 149,338	$ 153,311