Quarterly Financial Data Quarterly Financial Information Table (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended												12 Months Ended
	Dec. 31, 2017		Sep. 30, 2017		Jul. 01, 2017		Apr. 01, 2017		Dec. 31, 2016	Oct. 01, 2016	Jul. 02, 2016	Apr. 02, 2016	Dec. 31, 2017		Dec. 31, 2016		Dec. 31, 2015
Effect of Fourth Quarter Events [Line Items]
Loss on extinguishment of debt					$ 58,759								$ 59,545		$ 0		$ 2,943
Quarterly Financial Information, Income Taxes, Significant Variation, Description	$ 124,748
Sales	7,633,870		$ 6,953,740		6,465,346		$ 5,759,552		$ 6,442,891	$ 5,936,092	$ 5,972,101	$ 5,474,177	26,812,508		23,825,261		23,282,020
Gross Profit	930,128		843,358		823,966		759,887		823,348	773,162	798,791	748,898	3,357,339		3,144,199		3,035,250
Operating Income (Loss)	270,914		235,992		229,822		191,722		254,899	198,684	223,592	181,364	928,450		858,539		824,482
Net income attributable to shareholders	$ 53,885	[1]	$ 134,630		$ 99,679	[2]	$ 113,768		$ 164,518	$ 117,727	$ 134,270	$ 106,235	$ 401,962		$ 522,750		$ 497,726
Basic	$ 0.61	[3]	$ 1.52	[3]	$ 1.12	[3]	$ 1.27	[3]	$ 1.84	$ 1.29	$ 1.46	$ 1.16	$ 4.53		$ 5.75		$ 5.26
Diluted	$ 0.60	[3]	$ 1.50	[3]	$ 1.11	[3]	$ 1.26	[3]	$ 1.81	$ 1.28	$ 1.45	$ 1.14	$ 4.48	[4]	$ 5.68	[4]	$ 5.20	[4]

[1] U.S. Tax Act expense of $124.7 million during the fourth quarter of 2017.

[2] a loss on extinguishment of debt of $58.8 million

[3] Quarterly net income per share is calculated using the weighted-average shares outstanding during each quarterly period, while net income per share for the full year is calculated using the weighted-average shares outstanding during the year. Therefore, the sum of the net income per share for each of the four quarters may not equal the net income per share for the full year.

[4] Stock-based compensation awards for the issuance of 380 shares, 766 shares, and 658 shares for the years ended December 31, 2017, 2016, and 2015, respectively, were excluded from the computation of net income per share on a diluted basis as their effect was anti-dilutive.