Significant Accounting Policies (Details Textuals) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended	9 Months Ended
	Sep. 30, 2012 percent	Sep. 30, 2011 percent	Jun. 30, 2011	Sep. 30, 2012 percent	Sep. 30, 2011 percent	Dec. 31, 2011
Significant Accounting Policies [Line Items]
Effective Income Tax Rate, Continuing Operations	32.00%	35.00%		32.00%	24.00%
Current Income Tax Expense (Benefit)			$ 88
Unrecognized Tax Benefits	3			3		4
Unrecognized Tax Benefits, Decreases Resulting from Settlements with Taxing Authorities				30
Collateral Already Posted, Aggregate Fair Value	24			24
Cash Collateral Paid or Received for Derivative Assets	0			0
Cash Collateral Paid or Received for Derivative Liabilities	1			1
Cash Collateral Paid	5			5
Cash Collateral Received	$ 30			$ 30
Minimum [Member]
Significant Accounting Policies [Line Items]
Minimum FInite Lived Intangible Assets Useful Life				3 years
Maximum [Member]
Significant Accounting Policies [Line Items]
Minimum FInite Lived Intangible Assets Useful Life				20 years