CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Thousands, $ in Thousands		3 Months Ended							12 Months Ended
		Mar. 31, 2018		Dec. 31, 2017	Sep. 30, 2017	Jul. 01, 2017	Apr. 01, 2017		Dec. 31, 2017
Sales		$ 6,875,613	[1]	$ 7,539,449	$ 6,856,108	$ 6,422,226	$ 5,736,780	[1]	$ 26,554,563
Cost of sales		6,006,669		6,610,269	6,013,541	5,598,202	4,975,583		23,197,595
Gross Profit		868,944					761,197
Operating expenses:
Selling, general, and administrative expenses		562,969					515,526
Depreciation and amortization		47,247					37,141
Loss on disposition of businesses, net		1,562					0
Restructuring, integration, and other charges		21,171					15,505
Total operating expenses		632,949					568,172
Operating income		235,995		286,824	235,441	230,446	193,025		945,736
Equity in earnings (losses) of affiliated companies		(673)					925
Gain (loss) on investments, net		(2,452)					1,982
Post-retirement expense		1,231					1,800
Interest and other financing expense, net		45,179					38,249
Income before income taxes		186,460					155,883
Provision for income taxes		46,590					39,564
Consolidated net income		139,870					116,319
Noncontrolling interests		776					1,582
Net income attributable to shareholders		$ 139,094		$ 53,653	$ 134,064	$ 99,722	$ 114,737		$ 402,176
Net income per share:
Basic		$ 1.58					$ 1.29
Diluted	[2]	$ 1.56					$ 1.27
Weighted-average shares outstanding:
Basic		87,955					89,262
Diluted		89,035					90,541

[1] Includes sales related to the United States of $2,649,668 and $2,342,128 for the first quarter of 2018 and 2017, respectively.

[2] Stock-based compensation awards for the issuance of 415 and 244 for the first quarter of 2018 and 2017, respectively, were excluded from the computation of net income per share on a diluted basis as their effect was anti-dilutive.