Debt (Tables)

9 Months Ended

Sep. 30, 2017

Debt Table

Debt at each of the balance sheet periods consisted of:

	September 30, 2017				September 30, 2016				December 31, 2016
(millions)	Carrying Value		Fair Value		Carrying Value		Fair Value		Carrying Value		Fair Value
3.75% Senior Notes due 2021	$	498.7	$	525.7	$	498.4	$	544.2	$	498.4	$	528.8
2.45% Senior Notes due 2027	496.0		475.3		495.6		497.5		495.8		464.6
6 5/8% Senior Notes due 2029	296.0		388.3		295.8		402.6		295.9		380.1
6.25% Senior Notes due 2032	395.3		518.7		395.1		533.3		395.2		499.0
4.35% Senior Notes due 2044	346.5		379.8		346.4		403.0		346.4		362.3
3.70% Senior Notes due 2045	395.2		392.6		395.1		418.7		395.1		372.5
4.125% Senior Notes due 2047	841.2		894.2		0		0		0		0
6.70% Fixed-to-Floating Rate Junior Subordinated Debentures due 2067	0		0		593.9		572.3		594.1		581.2
Other debt instruments	43.3		43.3		133.6		133.6		127.3		127.3
Total	$	3,312.2	$	3,617.9	$	3,153.9	$	3,505.2	$	3,148.2	$	3,315.8

Other debt instruments

Schedule of Carrying Values and Estimated Fair Values of Debt Instruments [Table Text Block]

The other debt instruments reported in the table above represent ARX indebtedness and consist of:

	September 30, 2017			September 30, 2016			December 31, 2016
($ in millions) Type of debt instrument	Number of Instruments	Carrying Value		Number of Instruments	Carrying Value		Number of Instruments	Carrying Value		Stated Maturity Date(s)
Term loans	2	$	43.3	2	$	68.4	2	$	62.1	December 2018 and 2019
Junior subordinated notes1	0	0		2	41.2		2	41.2		June 2036 and 2037
Senior notes1	0	0		4	24.0		4	24.0		Various2
Total		$	43.3		$	133.6		$	127.3

¹ The notes were redeemed during the third quarter 2017 (discussed below).

² The senior notes original maturity dates were May 2033, April 2034, December 2034, and June 2035.