Debt and Financing (Tables)

12 Months Ended

Dec. 31, 2015

Debt Instruments [Abstract]

Long-term Debt

The following table summarizes the Company's short-term and long-term debt (in millions, except percentages):

	As of December 31, 2015
	Amount			Effective Interest Rates
Senior notes:
3.10% fixed-rate notes, due March 2016	$	300.0		3.25	%
3.30% fixed-rate notes, due June 2020	300.0			3.47	%
4.60% fixed-rate notes, due March 2021	300.0			4.69	%
4.50% fixed-rate notes, due March 2024	350.0			4.63	%
4.35% fixed-rate notes, due June 2025	300.0			4.47	%
5.95% fixed-rate notes, due March 2041	400.0			6.03	%
Total senior notes	1,950.0
Unaccreted discount	(1.3		)
Total	$	1,948.7
Reported as:
Short-term debt	$	299.9
Long-term debt	1,648.8
Total	$	1,948.7