Debt and Credit Agreements Schedule of Long-term Debt Instruments (Tables)

12 Months Ended

Dec. 31, 2018

Debt Disclosure [Abstract]

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

A summary of the carrying amounts and fair values of our long-term debt is listed below.

	Effective Interest Rate		December 31,
			2018				2017
			Book Value		Fair Value 1		Book Value		Fair Value 1
3.50% Senior Notes due 2020 (less unamortized discount and issuance costs of $0.8 and $2.6, respectively)	3.89	%	$	496.6	$	499.9	$	—	$	—
3.75% Senior Notes due 2021 (less unamortized discount and issuance costs of $0.3 and $2.9, respectively)	3.98	%	496.8		503.2		—		—
4.00% Senior Notes due 2022 (less unamortized discount and issuance costs of $1.0 and $0.8, respectively)	4.13	%	248.2		250.3		247.6		259.0
3.75% Senior Notes due 2023 (less unamortized discount and issuance costs of $0.6 and $1.7, respectively)	4.32	%	497.7		491.4		497.1		513.2
4.20% Senior Notes due 2024 (less unamortized discount and issuance costs of $0.5 and $2.2, respectively)	4.24	%	497.3		492.6		496.7		524.2
4.65% Senior Notes due 2028 (less unamortized discount and issuance costs of $1.7 and $4.3, respectively)	4.78	%	494.0		494.1		—		—
5.40% Senior Notes due 2048 (less unamortized discount and issuance costs of $2.8 and $5.5, respectively)	5.48	%	491.7		474.1		—		—
Term Loan due 2021 - LIBOR plus 1.25%			400.0		400.0		—
Other notes payable and capitalized leases			38.0		38.0		46.2		46.2
Total long-term debt			3,660.3				1,287.6
Less: current portion			0.1				2.0
Long-term debt, excluding current portion			$	3,660.2			$	1,285.6

1 See Note 12 for information on the fair value measurement of our long-term debt.