Allowance for Credit Losses - Forecasted Economonic Scenarios (Details)	Dec. 31, 2020		Jun. 30, 2020	Jan. 01, 2020
Measurement of ECL Measurements [Line Items]
GDP growth rate (percent)			9.00%
Forecast, Quarter ended June 30, 2021 [Member]
Measurement of ECL Measurements [Line Items]
Unemployment rate (percent)	6.80%			3.90%
GDP growth rate (percent)	9.20%	[1]		1.90%
Forecast, Quarter ended December 31, 2021 [Member]
Measurement of ECL Measurements [Line Items]
Unemployment rate (percent)	6.20%			4.00%
GDP growth rate (percent)	5.30%			2.00%

[1] Represents the change in forecasted GDP for the quarter ended June 30, 2021 relative to the GDP for the quarter ended June 30, 2020. The GDP year-over-year growth rate for the quarter ended June 30, 2020 was a decline of 9.0 percent.