Commitments and Contingencies - Schedule of Direct Exposure to Puerto Rico Government by Maturity (Details) - PR Government direct exposure - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2021	Dec. 31, 2020
Direct exposure to the puerto rico government by maturity
Outstanding concentration of risk	$ 345,783	$ 377,000
Total concentration of risk	364,840
Investment Portfolio
Direct exposure to the puerto rico government by maturity
Outstanding concentration of risk	30,193	35,000
Loans
Direct exposure to the puerto rico government by maturity
Outstanding concentration of risk	315,590	$ 342,000
From PR Central Government
Direct exposure to the puerto rico government by maturity
Outstanding concentration of risk	48
Total concentration of risk	48
From PR Central Government | After 1 and within 5 years
Direct exposure to the puerto rico government by maturity
Outstanding concentration of risk	6
Total concentration of risk	6
From PR Central Government | After 5 to 10 years
Direct exposure to the puerto rico government by maturity
Outstanding concentration of risk	5
Total concentration of risk	5
From PR Central Government | After 10 years
Direct exposure to the puerto rico government by maturity
Outstanding concentration of risk	37
Total concentration of risk	37
From PR Central Government | Investment Portfolio
Direct exposure to the puerto rico government by maturity
Outstanding concentration of risk	48
From PR Central Government | Investment Portfolio | After 1 and within 5 years
Direct exposure to the puerto rico government by maturity
Outstanding concentration of risk	6
From PR Central Government | Investment Portfolio | After 5 to 10 years
Direct exposure to the puerto rico government by maturity
Outstanding concentration of risk	5
From PR Central Government | Investment Portfolio | After 10 years
Direct exposure to the puerto rico government by maturity
Outstanding concentration of risk	37
From PR Central Government | Loans
Direct exposure to the puerto rico government by maturity
Outstanding concentration of risk	0
From PR Central Government | Loans | After 1 and within 5 years
Direct exposure to the puerto rico government by maturity
Outstanding concentration of risk	0
From PR Central Government | Loans | After 5 to 10 years
Direct exposure to the puerto rico government by maturity
Outstanding concentration of risk	0
From PR Central Government | Loans | After 10 years
Direct exposure to the puerto rico government by maturity
Outstanding concentration of risk	0
From Municipalities
Direct exposure to the puerto rico government by maturity
Outstanding concentration of risk	345,735
Total concentration of risk	364,792
From Municipalities | Within 1 year
Direct exposure to the puerto rico government by maturity
Outstanding concentration of risk	72,890
Total concentration of risk	72,890
From Municipalities | After 1 and within 5 years
Direct exposure to the puerto rico government by maturity
Outstanding concentration of risk	85,266
Total concentration of risk	104,323
From Municipalities | After 5 to 10 years
Direct exposure to the puerto rico government by maturity
Outstanding concentration of risk	132,092
Total concentration of risk	132,092
From Municipalities | After 10 years
Direct exposure to the puerto rico government by maturity
Outstanding concentration of risk	55,487
Total concentration of risk	55,487
From Municipalities | Investment Portfolio
Direct exposure to the puerto rico government by maturity
Outstanding concentration of risk	30,145
From Municipalities | Investment Portfolio | Within 1 year
Direct exposure to the puerto rico government by maturity
Outstanding concentration of risk	4,240
From Municipalities | Investment Portfolio | After 1 and within 5 years
Direct exposure to the puerto rico government by maturity
Outstanding concentration of risk	14,395
From Municipalities | Investment Portfolio | After 5 to 10 years
Direct exposure to the puerto rico government by maturity
Outstanding concentration of risk	11,280
From Municipalities | Investment Portfolio | After 10 years
Direct exposure to the puerto rico government by maturity
Outstanding concentration of risk	230
From Municipalities | Loans
Direct exposure to the puerto rico government by maturity
Outstanding concentration of risk	315,590
From Municipalities | Loans | Within 1 year
Direct exposure to the puerto rico government by maturity
Outstanding concentration of risk	68,650
From Municipalities | Loans | After 1 and within 5 years
Direct exposure to the puerto rico government by maturity
Outstanding concentration of risk	70,871
From Municipalities | Loans | After 5 to 10 years
Direct exposure to the puerto rico government by maturity
Outstanding concentration of risk	120,812
From Municipalities | Loans | After 10 years
Direct exposure to the puerto rico government by maturity
Outstanding concentration of risk	$ 55,257