Commitments and Contingencies (Tables)

12 Months Ended

Dec. 31, 2017

Commitments and Contingencies Disclosure [Abstract]

Schedule of Commitments and Contingencies

	December 31,
(Dollars in millions)	2017		2016
Letters of credit	$	2,466	$	2,786
Carrying amount of the liability for letters of credit	21		27
Investments in affordable housing projects:
Carrying amount	1,948		1,719
Amount of future funding commitments included in carrying amount	928		738
Lending exposure	561		495
Tax credits subject to recapture	471		413
Private equity investments	471		417
Future funding commitments to private equity investments	143		199

Schedule of Pledged Assets

The following table provides the total carrying amount of pledged assets by asset type, of which the majority are pursuant to agreements that do not permit the other party to sell or repledge the collateral. Assets related to employee benefit plans are excluded from the following table.

	December 31,
(Dollars in millions)	2017		2016
Pledged securities	$	14,636	$	15,549
Pledged loans	74,718		75,015