Fair Value Measurements (Summary of Assets And Liabilities Measured at Fair Value) (Detail) - USD ($) $ in Thousands	Jun. 25, 2017	Dec. 31, 2016	Jun. 26, 2016
Fair Value
Assets:
Cash equivalents	$ 988,476	$ 759,984	$ 864,670
Marketable securities	44,156	43,638	42,721
Derivatives	458	29,034	9,528
Liabilities:
Derivatives, liabilities	4,865	142	1,605
Fair Value, Measurements, Recurring
Assets:
Cash equivalents	625,485	531,519	549,426
Marketable securities	44,156	43,638	42,721
Derivatives	458	29,034	9,528
Assets, fair value	670,099	604,191	601,675
Liabilities:
Derivatives, liabilities	4,865	142	1,605
Fair Value, Measurements, Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets:
Cash equivalents	375,550	426,266	392,800
Marketable securities	44,156	38,119	37,651
Derivatives	0	0	0
Assets, fair value	419,706	464,385	430,451
Liabilities:
Derivatives, liabilities	0	0	0
Fair Value, Measurements, Recurring | Significant Other Observable Inputs (Level 2)
Assets:
Cash equivalents	249,935	105,253	156,626
Marketable securities	0	5,519	5,070
Derivatives	458	29,034	9,528
Assets, fair value	250,393	139,806	171,224
Liabilities:
Derivatives, liabilities	4,865	142	1,605
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	2,700	9,300	3,600
Fair Value, Measurements, Nonrecurring | Significant Other Observable Inputs (Level 2) | Fair Value
Liabilities:
Repossessed inventory	$ 17,900	$ 19,300	$ 15,300