Regulatory Capital Requirements - Capital Conservation Buffer (Details)	Jun. 30, 2020	Dec. 31, 2019
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Effective CET1 capital to risk-weighted assets (as a percent)	4.50%	4.50%
Effective Tier 1 capital to risk-weighted assets (as a percent)	11.86%	11.88%
Effective total capital to risk-weighted assets (as a percent)	13.11%	12.81%
Capital conservation buffer
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Capital requirements above regulatory rate (as a percent)	2.50%
Effective CET1 capital to risk-weighted assets (as a percent)	7.00%
Effective Tier 1 capital to risk-weighted assets (as a percent)	8.50%
Effective total capital to risk-weighted assets (as a percent)	10.50%