Securities - Securities Transferred From AFS to HTM (Details) - USD ($) $ in Billions	Dec. 31, 2015	Dec. 31, 2013
Securities [Abstract]
Aggregate amortized cost of available-for-sale securities transferred to held-to-maturity	$ 11.6	$ 7.3
Fair value of available-for-sale securities transferred to held-to-maturity	$ 11.6	$ 7.0

Available-for-Sale Securities, Transferred Security, Amortized Cost

No definition available.

Name:	bk_AvailableforSaleSecuritiesTransferredSecurityAmortizedCost
Namespace Prefix:	bk_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant