Income Taxes - Analysis of the Effective Tax Rate (Details) - USD ($) $ in Millions			12 Months Ended
Jan. 01, 2018	Dec. 22, 2017	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Federal income tax rate	21.00%	35.00%	21.00%	21.00%	35.00%
Net tax effects of:
State income taxes, net of federal income tax benefit			(13.00%)	7.00%	5.00%
Effective Income Tax Rate Reconciliation, Goodwill Impairment			(45.00%)	0.00%	0.00%
Tax-exempt interest income			2.00%	(1.00%)	(1.00%)
Effective Income Tax Rate Reconciliation, Deduction, Amount			4.00%	(2.00%)	(3.00%)
Amortization of LIHC investments			(20.00%)	12.00%	14.00%
Tax credits			40.00%	(25.00%)	(21.00%)
Effective Income Tax Rate Reconciliation, Nondeductible Expense, Life Insurance, Percent			(2.00%)	1.00%	0.00%
Effective Income Tax Rate Reconciliation, Valuation Release			1.00%	0.00%	0.00%
Effective Income Tax Rate Reconciliation, Change in Enacted Tax Rate, Amount			0.00%	(2.00%)	(8.00%)
Effective Income Tax Rate Reconciliation, State Refunds, Percent			0.00%	(5.00%)	0.00%
Other			0.00%	(1.00%)	1.00%
Effective tax rate			(12.00%)	5.00%	22.00%
One Time Tax Benefit from Change in Federal Corporate Tax Rate			$ 101

Effective Income Tax Rate Reconciliation, Goodwill Impairment

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One time tax benefit from the Tax Cuts & Jobs Act which reduced the federal corporate income tax rate from 35% to 21% effective January 1, 2018.

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