Long-Term Debt (Schedule Of Long-Term Debt) (Details) - USD ($) $ in Millions		6 Months Ended
		Jun. 30, 2016	Dec. 31, 2015
Long-term debt [Line Items]
Less current portion		$ (60)	$ (54)
Total long-term debt		2,714	2,698
Vehicle Capital Leases [Member]
Long-term debt [Line Items]
Vehicle capital leases	[1]	$ 67	47
Borrowing margin (as a percent)		2.45%
Variable rate basis		one-month LIBOR
Senior Secured Term Loan Facility Maturing In 2021 [Member]
Long-term debt [Line Items]
Long-term debt	[2]	$ 2,328	2,336
Unamortized debt issuance costs		19	21
Unamortized original issue discount		15	17
Revolving Credit Facility Maturing In 2019 [Member]
Long-term debt [Line Items]
Long-term debt
7.10% Notes Maturing In 2018 [Member]
Long-term debt [Line Items]
Long-term debt	[3]	$ 76	75
Interest rate (as a percent)		7.10%
7.45% Notes Maturing In 2027 [Member]
Long-term debt [Line Items]
Long-term debt	[3]	$ 165	164
Interest rate (as a percent)		7.45%
7.25% Notes Maturing In 2038 [Member]
Long-term debt [Line Items]
Long-term debt	[3]	$ 65	65
Interest rate (as a percent)		7.25%
7.10% Notes, 7.45% Notes, 7.25% Notes Collectively [Member]
Long-term debt [Line Items]
Unamortized fair value adjustments related to purchase accounting		$ 51	53
Other [Member]
Long-term debt [Line Items]
Long-term debt		$ 73	$ 65

[1] The Company has entered into a fleet management services agreement (the "Fleet Agreement") which, among other things, allows the Company to obtain fleet vehicles through a leasing program. All leases under the Fleet Agreement are capital leases for accounting purposes. The lease rental payments include an interest component calculated using a variable rate based on one-month LIBOR plus other contractual adjustments and a borrowing margin totaling 2.45 percent.

[2] As of June 30, 2016 and December 31, 2015, presented net of $19 million and $21 million, respectively, in unamortized debt issuance costs and $15 million and $17 million, respectively, in unamortized original issue discount paid.

[3] As of June 30, 2016 and December 31, 2015, collectively presented net of $51 million and $53 million, respectively, of unamortized fair value adjustments related to purchase accounting, which increases the effective interest rate from the coupon rates shown above.