| 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. |
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| 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 |
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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).
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