Regulatory Capital Requirements - Required Ratios (Details)	12 Months Ended
	Dec. 31, 2019	Jan. 01, 2019	Dec. 31, 2018	Jan. 01, 2016
Banking and Thrift [Abstract]
Minimum ratio of Common Equity Tier 1 capital to risk-weighed assets		4.50%
Minimum ratio of Common Equity Tier 1 capital to risk-weighed assets, capital conservation buffer		2.50%		0.625%
Tier 1 common equity, (to risk-weighted assets), Minimum Capital Requirement, Ratio (as a percent)		7.00%	6.38%
Minimum ratio of Tier 1 capital to risk-weighted assets		6.00%
Tier 1 capital (to risk-weighted assets), Minimum Capital Requirement, Ratio (as a percent)		8.50%	7.88%
Minimum ratio of Total capital to risk-weighted assets		8.00%
Capital Required for Capital Adequacy to Risk Weighted Assets		10.50%	9.88%
Tier 1 capital (to average assets), Minimum Capital Requirement, Ratio (as a percent)		4.00%	4.00%
Phase-in period	4 years