Fair Value (Summary of Assets And Liabilities Measured at Fair Value) (Detail) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018	Apr. 01, 2018
Fair Value, Measurements, Recurring
Assets:
Cash equivalents	$ 498,207	$ 998,601	$ 653,124
Marketable securities	59,899	54,250	49,402
Derivatives	16,083	15,071	3,613
Assets, fair value	574,189	1,067,922	706,139
Liabilities:
Derivatives, liabilities	7,733	5,316	22,850
Fair Value, Measurements, Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets:
Cash equivalents	321,300	728,800	326,324
Marketable securities	49,896	44,243	49,402
Derivatives	0	0	0
Assets, fair value	371,196	773,043	375,726
Liabilities:
Derivatives, liabilities	0	0	0
Fair Value, Measurements, Recurring | Significant Other Observable Inputs (Level 2)
Assets:
Cash equivalents	176,907	269,801	326,800
Marketable securities	10,003	10,007	0
Derivatives	16,083	15,071	3,613
Assets, fair value	202,993	294,879	330,413
Liabilities:
Derivatives, liabilities	7,733	5,316	22,850
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	9,300	9,700	8,300
Fair Value, Measurements, Nonrecurring | Significant Other Observable Inputs (Level 2) | Fair Value
Liabilities:
Repossessed inventory	$ 21,400	$ 20,200	$ 23,800