Quarterly Financial Data (Tables)

12 Months Ended

Dec. 31, 2018

Quarterly Financial Information Disclosure [Abstract]

Quarterly Financial Information [Table Text Block]

A summary of the company's consolidated quarterly results of operations is as follows:

	First Quarter		Second Quarter (b)		Third Quarter		Fourth Quarter (c)
2018
Sales	$	6,875,613	$	7,392,528	$	7,490,445	$	7,918,182
Gross profit	868,944		932,820		923,778		975,370
Operating income	235,995		286,827		290,310		334,380
Net income attributable to shareholders	139,094		169,915		176,533		230,653
Net income per share (a):
Basic	$	1.58	$	1.94	$	2.02	$	2.66
Diluted	$	1.56	$	1.92	$	1.99	$	2.63
2017 (Adjusted)
Sales	$	5,736,780	$	6,422,226	$	6,856,108	$	7,539,449
Gross profit	761,197		824,024		842,567		929,180
Operating income	193,025		230,446		235,441		286,824
Net income attributable to shareholders	114,737		99,722		134,064		53,653
Net income per share (a):
Basic	$	1.29	$	1.12	$	1.52	$	0.61
Diluted	$	1.27	$	1.11	$	1.50	$	0.60

(a) 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.

(b) Net income attributable to shareholders includes a loss on extinguishment of debt of $58.8 million during the second quarter of 2017.

(c) Net income attributable to shareholders includes a U.S. Tax Act benefit of $28.3 million and expense of $124.7 million during the fourth quarter of 2018 and 2017, respectively.

New Accounting Pronouncements and Changes in Accounting Principles [Text Block]

The following table presents the effect of the adoption of Topic 606, ASU No. 2017-07, and other prior period reclassifications for each quarter of 2017 (see Note 1).

	First Quarter				Second Quarter				Third Quarter				Fourth Quarter
	As Previously Reported		Adjusted for New Standards		As Previously Reported		Adjusted for New Standards		As Previously Reported		Adjusted for New Standards		As Previously Reported		Adjusted for New Standards
2017
Sales	$	5,759,552	$	5,736,780	$	6,465,346	$	6,422,226	$	6,953,740	$	6,856,108	$	7,633,870	$	7,539,449
Cost of sales	4,999,665		4,975,583		5,641,380		5,598,202		6,110,382		6,013,541		6,703,742		6,610,269
Operating income	191,722		193,025		229,822		230,446		235,992		235,441		270,914		286,824
Net income attributable to shareholders	$	113,768	$	114,737	$	99,679	$	99,722	$	134,630	$	134,064	$	53,885	$	53,653

Operating income for the fourth quarter of 2017 was impacted by a reclassification of pension settlement expense of $16,706 due to the implementation of ASU No. 2017-07. The settlement expense was reclassified to "Employee benefit plan expense" (see Note 13).