Allowance for Credit Losses - Forecasted Economonic Scenarios (Details)		Mar. 31, 2021	Dec. 31, 2020	Jun. 30, 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)		6.00%	6.80%
GDP growth rate (percent)	[1]	11.00%	9.20%
Forecast, Quarter ended December 31, 2021 [Member]
Measurement of ECL Measurements [Line Items]
Unemployment rate (percent)		5.50%	6.20%
GDP growth rate (percent)		4.30%	5.30%
Forecast, Quarter ended June 30, 2022 [Member]
Measurement of ECL Measurements [Line Items]
Unemployment rate (percent)		4.90%	5.90%
GDP growth rate (percent)		3.70%	3.10%
Forecast, Quarter ended December 31, 2022 [Member]
Measurement of ECL Measurements [Line Items]
Unemployment rate (percent)		4.40%	5.40%
GDP growth rate (percent)		3.00%	1.80%

[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.