Related Party (Cost Allocation Agreements with Affiliates) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Related Party Transactions [Abstract]
Allocated Lease Expense	$ 1	$ 1	$ 2	$ 2
Allocated Sub-Lease Rental Income	1	1	1	2
Commissions and Fees Paid to PAD	$ 43	$ 45	$ 85	$ 95