Intangible Assets (Tables)

3 Months Ended

Mar. 31, 2012

Intangible Assets [Abstract]

Intangible Assets with definite lives

		$000,000,000	$000,000,000	$000,000,000		$000,000,000	$000,000,000	$000,000,000
	As of March 31, 2012				As of December 31, 2011
(millions)		Gross Carrying Amount	Accumulated Amortization	Net		Gross Carrying Amount	Accumulated Amortization	Net
Intangible Assets with Definite Lives:
Customer relationships		$    70	$    (35)	$    35		$    70	$    (34)	$    36
Other		9	(6)	3		9	(5)	4
Total		$    79	$    (41)	$    38		$    79	$    (39)	$    40

Estimated annual amortization expense intangible assets

		$000,000,		$000,000,		$000,000,		$000,000,		$000,000,		$000,000,
(millions)	2012		2013		2014		2015		2016		2017
Estimated annual amortization expense	$	8	$	7	$	7	$	7	$	7	$	2

Intangible Assets with Indefinite Lives

	As of March 31, 2012						As of December 31, 2011
(millions)		Gross Carrying Amount		Impairment Charges		Net		Gross Carrying Amount		Impairment Charges		Net
Intangible Assets with Indefinite Lives:
Trade names	$	22	$	-	$	22	$	22	$	-	$	22
Other		8		-		8		8		-		8
Total	$	30	$	-	$	30	$	30	$	-	$	30