Investment Securities - Summary of Investment Securities (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Available-for-sale securities
Amortized Cost	$ 2,115	$ 2,206
Gross Unrealized Gains	8	4
Gross Unrealized Losses	(7)	(68)
Fair Value	2,116	2,142
Held-to-maturity securities
Amortized Cost	598	703
Gross Unrealized Gains	3	0
Gross Unrealized Losses	(2)	(22)
Fair Value	599	681
Agency - Commercial
Available-for-sale securities
Amortized Cost	948	1,413
Gross Unrealized Gains	2	4
Gross Unrealized Losses	(3)	(43)
Fair Value	947	1,374
Held-to-maturity securities
Amortized Cost	306	349
Gross Unrealized Gains	0	0
Gross Unrealized Losses	(1)	(13)
Fair Value	305	336
Agency - Residential
Available-for-sale securities
Amortized Cost	1,015	686
Gross Unrealized Gains	4	0
Gross Unrealized Losses	(4)	(24)
Fair Value	1,015	662
Held-to-maturity securities
Amortized Cost	292	354
Gross Unrealized Gains	3	0
Gross Unrealized Losses	(1)	(9)
Fair Value	294	345
Corporate debt obligations
Available-for-sale securities
Amortized Cost	76	41
Gross Unrealized Gains	1	0
Gross Unrealized Losses	0	0
Fair Value	77	41
Municipal obligations
Available-for-sale securities
Amortized Cost	31	33
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	(1)
Fair Value	31	32
Other MBS
Available-for-sale securities
Amortized Cost	44	32
Gross Unrealized Gains	1	0
Gross Unrealized Losses	0	0
Fair Value	45	32
Certificates of Deposit
Available-for-sale securities
Amortized Cost	1	1
Gross Unrealized Gains		0
Gross Unrealized Losses		0
Fair Value	$ 1	$ 1

Amount, before tax, of unrealized gain in accumulated other comprehensive income (AOCI) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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