Fair Value Measurements (Summary of Assets And Liabilities Measured at Fair Value) (Detail) - USD ($) $ in Thousands	Sep. 25, 2016	Dec. 31, 2015	Sep. 27, 2015
Fair Value
Assets:
Cash equivalents	$ 790,284	$ 722,209	$ 1,368,554
Marketable securities	44,101	81,448	82,616
Derivatives	6,606	16,235	18,015
Liabilities:
Derivatives, liabilities	1,388	1,300	1,309
Fair Value, Measurements, Recurring
Assets:
Cash equivalents	526,228	555,910	1,111,571
Marketable securities	44,101	81,448	82,616
Derivatives	6,606	16,235	18,015
Assets, fair value	576,935	653,593	1,212,202
Liabilities:
Derivatives, liabilities	1,388	1,300	1,309
Fair Value, Measurements, Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets:
Cash equivalents	372,850	390,706	719,854
Marketable securities	39,063	36,256	35,258
Derivatives	0	0	0
Assets, fair value	411,913	426,962	755,112
Liabilities:
Derivatives, liabilities	0	0	0
Fair Value, Measurements, Recurring | Significant Other Observable Inputs (Level 2)
Assets:
Cash equivalents	153,378	165,204	391,717
Marketable securities	5,038	45,192	47,358
Derivatives	6,606	16,235	18,015
Assets, fair value	165,022	226,631	457,090
Liabilities:
Derivatives, liabilities	1,388	1,300	1,309
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	8,200	8,600	6,700
Fair Value, Measurements, Nonrecurring | Significant Other Observable Inputs (Level 2) | Fair Value
Liabilities:
Repossessed inventory	$ 18,500	$ 17,700	$ 16,600