Financial Instruments (Fair value hedges) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Fair value hedges
Gain (loss) on derivatives				$ (603.0)
Hedge ineffectiveness gain (loss)	$ 3.0	$ (9.0)	$ (82.0)	(74.0)
Interest Rate Contract
Fair value hedges
Gain (loss) on derivatives			(101.0)
Interest Rate Contract | Fair Value Hedges [Member]
Fair value hedges
Gain (loss) on derivatives	1,391.0	341.0	514.0	2,056.0
Gain (loss) on hedged items	(1,387.0)	(350.0)	(594.0)	(2,129.0)
Foreign Exchange Contract
Fair value hedges
Gain (loss) on derivatives			(2,486.0)
Foreign Exchange Contract | Fair Value Hedges [Member]
Fair value hedges
Gain (loss) on derivatives	(6.0)	(8.0)	(6.0)	(11.0)
Gain (loss) on hedged items	$ 5.0	$ 8.0	$ 4.0	$ 10.0