Derivative financial instruments - Offsetting liabilities (Details 4) - USD ($) $ in Millions	Dec. 31, 2015	Dec. 31, 2014
Derivatives
Gross amount of recognized liabilities	$ 384	$ 502
Derivative liabilities eligible for set-off in case of default	(215)	(216)
Cash collateral pledged	(3)	(3)
Net liability exposure	166	283
Total
Gross amount of recognized liabilities	384	502
Derivative liabilities eligible for set-off in case of default	(215)	(216)
Cash collateral pledged	(3)	(3)
Net liability exposure	$ 166	$ 283

Amount of right to receive cash collateral under master netting arrangements that have not been offset against derivative liabilities.

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Amount, after effects of master netting arrangements, of derivative liabilities, securities sold under agreements to repurchase and securities loaned offset against a right to receive collateral. Includes liabilities not subject to a master netting arrangement and not elected to be offset.

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Amount, before effects of master netting arrangements, of derivative liabilities, securities sold under agreements to repurchase and securities loaned. Includes liabilities elected not to be offset. Excludes liabilities not subject to a master netting arrangement.

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