Investments - Additional Information (Details) $ in Thousands	1 Months Ended	3 Months Ended	6 Months Ended	12 Months Ended
	Mar. 31, 2020	Jun. 30, 2021 USD ($) security	Jun. 30, 2021 USD ($) security	Dec. 31, 2020 USD ($) security
Investments, Debt and Equity Securities [Abstract]
Vertical risk retention interest	5.00%		5.00%
Trading investments		$ 35,908	$ 35,908	$ 16,923
Number of mortgage-backed securities with unrealized losses | security		41	41	14
Number of mortgage-backed securities | security		182	182	163
Par value of mortgage-backed securities pledged to FRB		$ 825,000	$ 825,000	$ 815,000
Gain on earlier equity securities investments		35,000	35,000
Non-marketable securities investment		69,000	69,000	26,000
Low income housing tax credit investments		71,000	71,000	54,000
Low income housing tax credit investments, liability for unfunded commitments		$ 33,000	33,000	19,000
Low income housing tax credit investments, tax credits and benefits			$ 1,000	$ 6,000
Low income housing tax credit investments, expected tax benefits recognized			25.00%