Debt (Components Of Debt) (Details) - USD ($) $ in Millions	1 Months Ended					3 Months Ended	6 Months Ended		12 Months Ended
	May 31, 2017	Mar. 31, 2017	Sep. 30, 2016	Jul. 31, 2016	Jan. 31, 2015	Jun. 30, 2017	Jun. 30, 2017	Jun. 30, 2016	Dec. 31, 2016	Nov. 30, 2015
Debt Instrument [Line Items]
Debt Instrument						$ 4,408.0	$ 4,408.0		$ 4,684.0
Unamortized Issuance Expense						(24.0)	(24.0)		(28.0)
Unamortized Debt Discount						(3.0)	(3.0)		(3.0)
Total						4,381.0	4,381.0		4,653.0
Net loss on extinguishment of debt						(10.0)	(11.0)
Short-term Debt [Member]
Debt Instrument [Line Items]
Debt Instrument						40.0	40.0		41.0
Unamortized Issuance Expense
Unamortized Debt Discount
Total						40.0	40.0		41.0
Short-term Debt [Member] | 7.35% Senior Notes due October 2017 [Member]
Debt Instrument [Line Items]
Debt Instrument						15.0	15.0		15.0
Unamortized Issuance Expense
Unamortized Debt Discount
Total						$ 15.0	$ 15.0		$ 15.0
Stated interest rate						7.35%	7.35%		7.35%
Maturity date, year and month							2017-10		2017-10
Short-term Debt [Member] | 7.125% Senior Notes due October 2017 [Member]
Debt Instrument [Line Items]
Debt Instrument						$ 25.0	$ 25.0		$ 25.0
Unamortized Issuance Expense
Unamortized Debt Discount
Total						$ 25.0	$ 25.0		$ 25.0
Stated interest rate						7.125%	7.125%		7.125%
Maturity date, year and month							2017-10		2017-10
Short-term Debt [Member] | 7.15% Senior Notes due June 2018 [Member]
Debt Instrument [Line Items]
Debt Instrument									$ 1.0
Unamortized Issuance Expense
Unamortized Debt Discount
Total									$ 1.0
Stated interest rate									7.15%
Maturity date, year and month									2018-06
Long-term Debt [Member]
Debt Instrument [Line Items]
Debt Instrument						$ 4,368.0	$ 4,368.0		$ 4,643.0
Unamortized Issuance Expense						(24.0)	(24.0)		(28.0)
Unamortized Debt Discount						(3.0)	(3.0)		(3.0)
Total						4,341.0	4,341.0		4,612.0
Net loss on extinguishment of debt	$ (10.0)
Long-term Debt [Member] | Term Loan 1 due December 2020 [Member]
Debt Instrument [Line Items]
Debt Instrument						327.0	327.0		327.0	$ 750.0
Unamortized Issuance Expense						(2.0)	(2.0)		(2.0)
Unamortized Debt Discount
Total						325.0	$ 325.0		$ 325.0
Variable interest rate							3.69%		3.22%
Maturity date, year and month							2020-12	2018-11	2020-12
Payments on long-term debt				$ 375.0
Accelerated maturity date, year and month if not amended, redeemed or refinanced							2019-10
Long-term Debt [Member] | Term Loan 2 due December 2020 [Member]
Debt Instrument [Line Items]
Debt Instrument						1,191.0	$ 1,191.0	$ 1,191.0	$ 1,191.0
Unamortized Issuance Expense						(9.0)	(9.0)		(10.0)
Unamortized Debt Discount
Total						$ 1,182.0	$ 1,182.0		$ 1,181.0
Variable interest rate							3.69%		3.22%
Maturity date, year and month							2020-12		2020-12
Accelerated maturity date, year and month if not amended, redeemed or refinanced							2019-10
Long-term Debt [Member] | 3.30% Senior Notes due January 2018 [Member]
Debt Instrument [Line Items]
Debt Instrument									$ 38.0
Unamortized Issuance Expense
Unamortized Debt Discount
Total									$ 38.0
Stated interest rate				5.05%	3.30%				3.30%
Maturity date, year and month					2018-01				2018-01
Debt repurchased	38.0
Purchase of note principal	38.0
Long-term Debt [Member] | 7.50% Senior Notes due February 2018 [Member]
Debt Instrument [Line Items]
Debt Instrument									$ 212.0
Unamortized Issuance Expense
Unamortized Debt Discount
Total									$ 212.0
Stated interest rate						7.50%	7.50%		7.50%
Maturity date, year and month							2018-02		2018-02
Debt repurchased	187.0	$ 25.0
Purchase of note principal	187.0
Net loss on extinguishment of debt		$ (1.0)
Long-term Debt [Member] | 7.15% Senior Notes due June 2018 [Member]
Debt Instrument [Line Items]
Debt Instrument									$ 25.0
Unamortized Issuance Expense
Unamortized Debt Discount
Total									$ 25.0
Stated interest rate						7.15%	7.15%		7.15%
Maturity date, year and month							2018-06		2018-06
Debt repurchased	26.0
Purchase of note principal	$ 26.0
Long-term Debt [Member] | 4.05% Senior Notes due January 2020 [Member]
Debt Instrument [Line Items]
Debt Instrument						$ 850.0	$ 850.0		$ 850.0
Unamortized Issuance Expense						(3.0)	(3.0)		(5.0)
Unamortized Debt Discount
Total						$ 847.0	$ 847.0		$ 845.0
Stated interest rate				5.80%	4.05%	4.05%	4.05%		4.05%
Maturity date, year and month					2020-01		2020-01		2020-01
Long-term Debt [Member] | 4.10% Senior Notes due March 2022 [Member]
Debt Instrument [Line Items]
Debt Instrument						$ 1,000.0	$ 1,000.0		$ 1,000.0
Unamortized Issuance Expense						(4.0)	(4.0)		(4.0)
Unamortized Debt Discount						(1.0)	(1.0)		(1.0)
Total						$ 995.0	$ 995.0		$ 995.0
Stated interest rate						4.10%	4.10%		4.10%
Maturity date, year and month							2022-03		2022-03
Long-term Debt [Member] | 4.95% Senior Notes due January 2025 [Member]
Debt Instrument [Line Items]
Debt Instrument						$ 1,000.0	$ 1,000.0		$ 1,000.0
Unamortized Issuance Expense						(6.0)	(6.0)		(7.0)
Unamortized Debt Discount						(2.0)	(2.0)		(2.0)
Total						$ 992.0	$ 992.0		$ 991.0
Stated interest rate				6.70%	4.95%	4.95%	4.95%		4.95%
Maturity date, year and month					2025-01		2025-01		2025-01
Long-term Debt [Member] | 2020 Senior Notes [Member]
Debt Instrument [Line Items]
Maturity date, year and month							2020-01		2020-01
Payments on long-term debt			$ 48.0
Amount to be amended, redeemed or refinanced to avoid acceleration							$ 765.0		$ 765.0
Senior Notes [Member]
Debt Instrument [Line Items]
Purchase of note principal				$ 700.0
Over LIBOR [Member] | Senior Notes [Member]
Debt Instrument [Line Items]
Increase in basis spread				1.75%