Derivative Instruments and Hedging Activities (Details Textual) (Interest rate swaps [Member], USD $) In Millions, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Senior Notes [Member]
Derivative Instruments and Hedging Activities (Textual) [Abstract]
Debt instrument outstanding	$ 30	$ 30
Interest Rate (in hundredths)	5.60%	5.60%
Borrowings [Member]
Derivative Instruments and Hedging Activities (Textual) [Abstract]
Debt instrument outstanding	$ 33	$ 33
Interest Rate (in hundredths)	3.30%	3.30%