Debt (Debt With A Contractual Term Greater Than One Year) (Detail) - USD ($) $ in Thousands	Sep. 24, 2017	Dec. 31, 2016	Sep. 25, 2016
Debt Instrument [Line Items]
Gross long-term debt	$ 6,138,192	$ 5,751,859	$ 5,870,761
Less: current portion of long-term debt, net of unamortized discount and debt issuance costs	(1,530,401)	(1,084,884)	(700,152)
Long-term debt, net	4,607,791	4,666,975	5,170,609
Secured Debt
Debt Instrument [Line Items]
Less: unamortized discount and debt issuance costs	(624)	(1,480)	(1,920)
Gross long-term debt	832,271	945,613	1,066,107
Secured Debt | Asset-backed Canadian commercial paper conduit facility
Debt Instrument [Line Items]
Long-term debt, gross	122,130	149,338	140,488
Secured Debt | Asset-Backed U.S. Commercial Paper Conduit Facility VIE [Member]
Debt Instrument [Line Items]
Long-term debt, gross	280,308	0	0
Secured Debt | Asset-backed securitization debt
Debt Instrument [Line Items]
Long-term debt, gross	430,457	797,755	927,539
Unsecured Debt
Debt Instrument [Line Items]
Less: unamortized discount and debt issuance costs	(21,567)	(21,242)	(22,834)
Unsecured Debt | 2.70% Medium-term notes due in 2017 par value, issued January 2012
Debt Instrument [Line Items]
Long-term debt, gross	$ 0	$ 400,000	$ 400,000
Debt instrument, stated percentage	2.70%	2.70%	2.70%
Unsecured Debt | 2.15% Medium-term notes due in 2020 par value, issued February 2015
Debt Instrument [Line Items]
Long-term debt, gross	$ 600,000	$ 600,000	$ 600,000
Debt instrument, stated percentage	2.15%	2.15%	2.15%
Unsecured Debt | 1.55% Medium-term notes due in 2017 par value, issued November 2014
Debt Instrument [Line Items]
Long-term debt, gross	$ 400,000	$ 400,000	$ 400,000
Debt instrument, stated percentage	1.55%	1.55%	1.55%
Unsecured Debt | 6.80% Medium-term notes due in 2018 par value, issued May 2008
Debt Instrument [Line Items]
Long-term debt, gross	$ 877,488	$ 877,488	$ 877,488
Debt instrument, stated percentage	6.80%	6.80%	6.80%
Unsecured Debt | 2.25% Medium-term notes due in 2019 par value, issued January 2016
Debt Instrument [Line Items]
Long-term debt, gross	$ 600,000	$ 600,000	$ 600,000
Debt instrument, stated percentage	2.25%	2.25%	2.25%
Unsecured Debt | Floating-Rate Medium Term Notes due 2019 [Member]
Debt Instrument [Line Items]
Long-term debt, gross	$ 150,000	$ 0	$ 0
Unsecured Debt | Two Point Four Percent Medium-Term Notes Due 2019 [Member]
Debt Instrument [Line Items]
Long-term debt, gross	$ 600,000	$ 600,000	$ 600,000
Debt instrument, stated percentage	2.40%	2.40%	2.40%
Unsecured Debt | Two Point Four Percent Medium-Term Notes Due 2020 [Member]
Debt Instrument [Line Items]
Long-term debt, gross	$ 350,000	$ 0	$ 0
Debt instrument, stated percentage	2.40%	2.40%	2.40%
Unsecured Debt | Two Point Eighty-five Percent Medium-Term Notes Due 2021 [Member] [Member]
Debt Instrument [Line Items]
Long-term debt, gross	$ 600,000	$ 600,000	$ 600,000
Debt instrument, stated percentage	2.85%	2.85%	2.85%
Unsecured Debt | Two Point Fifty-five Percent Medium-Term Notes Due 2022 [Member]
Debt Instrument [Line Items]
Long-term debt, gross	$ 400,000	$ 0	$ 0
Debt instrument, stated percentage	2.55%	2.55%	2.55%
Unsecured Debt | Three Point Five Percent Senior Unsecured Notes Due 2025 [Member]
Debt Instrument [Line Items]
Long-term debt, gross	$ 450,000	$ 450,000	$ 450,000
Debt instrument, stated percentage	3.50%	3.50%	3.50%
Unsecured Debt | Four Point Six Two Five Percent Senior Unsecured Notes Due 2045 [Member]
Debt Instrument [Line Items]
Long-term debt, gross	$ 300,000	$ 300,000	$ 300,000
Debt instrument, stated percentage	4.625%	4.625%	4.625%