Fair Value Measurements (Tables)

3 Months Ended

Mar. 31, 2016

Schedule Of Financial Assets And Liabilities Measured At Fair Value On A Recurring Basis

The following fair value hierarchy table categorizes information regarding our net financial assets measured at fair value on a recurring basis (in millions):



	Quoted Prices in Active Markets for Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)			Significant Unobservable Inputs (Level 3)		Total
As of March 31, 2016
Supplemental executive retirement plan assets	$	32.7	$	—		$	—	$	32.7
Derivatives, net	—		0.1			—		0.1
Total financial assets	$	32.7	$	0.1		$	—	$	32.8

As of December 31, 2015
Supplemental executive retirement plan assets	$	33.1	$	—		$	—	$	33.1
Total financial assets	$	33.1	$	—		$	—	$	33.1
Derivatives, net	—		(19.7		)	—		(19.7		)
Total financial liabilities	$	—	$	(19.7	)	$	—	$	(19.7	)

Schedule Of Carrying Values And Estimated Fair Values Of Debt Instruments

The carrying values and estimated fair values of our debt instruments were as follows (in millions):



	March 31, 2016				December 31, 2015
	Carrying Value		Estimated Fair Value		Carrying Value		Estimated Fair Value
4.70% Senior notes due 2021	$	1,477.8	$	1,048.1	$	1,476.7	$	1,254.0
5.75% Senior notes due 2044	993.7		514.6		993.5		707.1
6.875% Senior notes due 2020	986.5		663.8		990.9		850.5
5.20% Senior notes due 2025	692.7		389.4		692.5		505.2
4.50% Senior notes due 2024	619.9		349.7		619.7		417.4
8.50% Senior notes due 2019	561.9		441.8		566.4		510.2
7.875% Senior notes due 2040	379.4		161.6		379.8		244.0
7.20% Debentures due 2027	149.1		79.5		149.1		133.5
Total	$	5,861.0	$	3,648.5	$	5,868.6	$	4,621.9