Shares and Stockholders' Equity (Narrative) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended	6 Months Ended
Jun. 30, 2012	Jun. 30, 2012
Shares and Stockholders' Equity [Abstract]
Net income adjustment relating to equity classification of deferred compensation	$ 4	$ (2)

Value of accretion of temporary equity to its redemption value during the period. This item is an adjustment to net income necessary to derive net income apportioned to common stockholders and is to be distinguished from Temporary Equity, Accretion to Redemption Value (TemporaryEquityAccretionToRedemptionValue).

No definition available.

Name:	us-gaap_TemporaryEquityAccretionToRedemptionValueAdjustment
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration