LT Debt (Tables)

3 Months Ended

Mar. 31, 2018

Schedule of Long-term Debt Instruments [Abstract]

Schedule of Fair Value of Debt [Text Block]

The estimated fair market value, using quoted market prices, is as follows:

	March 31, 2018		December 31, 2017
3.00% notes, due 2018	$	—	$	300,500
6.00% notes, due 2020	220,500		224,000
5.125% notes, due 2021	137,000		139,000
3.50% notes, due 2022	349,000		355,000
4.50% notes, due 2023	309,500		315,500
3.25% notes, due 2024	479,000		491,000
4.00% notes, due 2025	348,500		356,500
7.50% senior debentures, due 2027	134,000		138,500
3.875% notes, due 2028	485,500		501,000

Schedule of Long-term Debt Instruments [Table Text Block]

Long-term debt consists of the following:

	March 31, 2018		December 31, 2017
Revolving credit facility	$	281,500	$	—
Asset securitization program	810,000		490,000
6.00% notes, due 2020	209,015		208,971
5.125% notes, due 2021	130,436		130,400
3.50% notes, due 2022	346,708		346,518
4.50% notes, due 2023	297,245		297,122
3.25% notes, due 2024	493,389		493,161
4.00% notes, due 2025	345,325		345,182
7.50% senior debentures, due 2027	109,714		109,694
3.875% notes, due 2028	493,694		493,563
Other obligations with various interest rates and due dates	16,024		18,434
	$	3,533,050	$	2,933,045