Income Taxes - Schedule of Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
DTAs:
Loans	$ 753	$ 0
Employee compensation and benefits	721	439
ALLL	366	369
Accruals and reserves	322	106
Net unrealized losses in AOCI	257	530
Operating lease liability	225	0
Federal and state NOLs and other carryforwards	156	16
Partnerships	0	77
Other	77	31
Total gross DTAs	2,877	1,568
Deferred Tax Assets, Valuation Allowance	130	0
Deferred Tax Assets, Net of Valuation Allowance	2,747	1,568
DTLs:
Pension	1,167	660
Equipment and auto leasing	932	375
Goodwill and other intangible assets	694	183
MSRs	491	248
Loans	0	104
ROU assets	146	0
Premises and equipment	162	56
Partnerships	23	0
Other	144	43
Total DTLs	3,759	1,669
Net DTL	$ (1,012)	$ (101)