Fair Value Measurements (Summary of Assets And Liabilities Measured at Fair Value) (Detail) - USD ($) $ in Thousands	Sep. 24, 2017	Dec. 31, 2016	Sep. 25, 2016
Fair Value
Assets:
Cash equivalents	$ 683,134	$ 759,984	$ 790,284
Marketable securities	45,726	43,638	44,101
Derivatives	724	29,034	6,606
Liabilities:
Derivatives, liabilities	32,414	142	1,388
Fair Value, Measurements, Recurring
Assets:
Cash equivalents	425,000	531,519	526,228
Marketable securities	45,726	43,638	44,101
Derivatives	724	29,034	6,606
Assets, fair value	471,450	604,191	576,935
Liabilities:
Derivatives, liabilities	32,414	142	1,388
Fair Value, Measurements, Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets:
Cash equivalents	425,000	426,266	372,850
Marketable securities	45,726	38,119	39,063
Derivatives	0	0	0
Assets, fair value	470,726	464,385	411,913
Liabilities:
Derivatives, liabilities	0	0	0
Fair Value, Measurements, Recurring | Significant Other Observable Inputs (Level 2)
Assets:
Cash equivalents	0	105,253	153,378
Marketable securities	0	5,519	5,038
Derivatives	724	29,034	6,606
Assets, fair value	724	139,806	165,022
Liabilities:
Derivatives, liabilities	32,414	142	1,388
Fair Value, Measurements, Recurring | Significant Unobservable Inputs (Level 3)
Assets:
Cash equivalents	0	0	0
Marketable securities	0	0	0
Derivatives	0	0	0
Assets, fair value	0	0	0
Liabilities:
Derivatives, liabilities	0	0	0
Fair Value, Measurements, Nonrecurring | Fair Value Adjustment
Liabilities:
Repossessed inventory	9,000	9,300	8,200
Fair Value, Measurements, Nonrecurring | Significant Other Observable Inputs (Level 2) | Fair Value
Liabilities:
Repossessed inventory	$ 21,300	$ 19,300	$ 18,500