Commitments And Contingent Liabilities (Leveraged Lease Investments) (Details) (USD $)	6 Months Ended	12 Months Ended		12 Months Ended
	Jun. 30, 2011	Dec. 31, 2011	Jun. 30, 2011 Leveraged Lease Investments [Member]	Dec. 31, 2010 Energy Holdings [Member]
Penalty percentage proposed for substantial understatement of tax liability			20.00%
Reduction in tax exposure				$ 1,100,000,000
Aggregate tax currently payable	264,000,000
Amount deposited with IRS to defray potential interest costs	320,000,000
Penalties from leverage lease investment tax examination	150,000,000
Rate of interest and penalty growth per quarter during 2011	2,000,000
Additional tax potentially due-low estimate	20,000,000
Additional tax potentially due-high estimate	40,000,000
Estimate of tax, interest and penalties potentially payable in 2010 for 1997 to 2000 tax years-low estimate		110,000,000
Estimate of tax, interest and penalties potentially payable in 2010 for 1997 to 2000 tax years-high estimate		300,000,000
Estimate of tax, interest and penalties potentially payable in 2010 for 2001 to 2003 tax years-low estimate		220,000,000
Estimate of tax, interest and penalties potentially payable in 2010 for 2001 to 2003 tax years-high estimate		550,000,000
Earnings impact consistent with broad settlement offer proposed by IRS-low estimate	120,000,000
Earnings impact consistent with broad settlement offer proposed by IRS-high estimate	$ 140,000,000