Fair Value Measurements (Summary Of Assets And Liabilities Measured at Fair Value) (Detail) (USD $)	Mar. 29, 2015	Dec. 31, 2014	Mar. 30, 2014
Fair Value, Measurements, Nonrecurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Repossessed Assets	$ 14,500,000	$ 13,400,000	$ 15,200,000
Fair Value, Measurements, Recurring [Member] | Balance [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	975,411,000	737,024,000	602,421,000
Investments, Fair Value Disclosure	94,886,000	91,140,000	126,122,000
Derivative Asset, Current	49,290,000	32,244,000	105,000
Assets, Fair Value Disclosure	1,119,587,000	860,408,000	728,648,000
Derivatives, liabilities	1,886,000	2,027,000	3,681,000
Fair Value, Measurements, Recurring [Member] | Quoted Prices In Active Markets For Identical Assets (Level 1) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	510,090,000	482,686,000	359,438,000
Investments, Fair Value Disclosure	37,667,000	33,815,000	33,182,000
Derivative Asset, Current	0	0	0
Assets, Fair Value Disclosure	547,757,000	516,501,000	392,620,000
Derivatives, liabilities	0	0	0
Fair Value, Measurements, Recurring [Member] | Significant Other Observable Inputs (Level 2) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	465,321,000	254,338,000	242,983,000
Investments, Fair Value Disclosure	57,219,000	57,325,000	92,940,000
Derivative Asset, Current	49,290,000	32,244,000	105,000
Assets, Fair Value Disclosure	571,830,000	343,907,000	336,028,000
Derivatives, liabilities	1,886,000	2,027,000	3,681,000
Fair Value, Measurements, Recurring [Member] | Significant Unobservable Inputs (Level 3) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash equivalents	0	0	0
Investments, Fair Value Disclosure	0	0	0
Derivative Asset, Current	0	0	0
Assets, Fair Value Disclosure	0	0	0
Derivatives, liabilities	0	0	0
Fair value, adjustment [Domain]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Repossessed Assets	$ 3,500,000	$ 5,000,000	$ 3,500,000