Commitments and Contingent Liabilities (Narrative) (Details) (USD $)	3 Months Ended						9 Months Ended
	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Dec. 31, 2013	Dec. 31, 2012
Loss Contingencies [Line Items]
Litigation charges	$ 18,000,000			$ 0			$ 68,000,000	$ 60,000,000
Average Wholesale Price Litigation [Member]
Loss Contingencies [Line Items]
Litigation charges	$ 18,000,000	$ 35,000,000	$ 15,000,000	$ 0	$ 44,000,000	$ 16,000,000	$ 68,000,000	$ 60,000,000