Variable interest entities ("VIEs") (Details) - USD ($)		12 Months Ended
	Oct. 26, 2021	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Variable Interest Entity [Line Items]
Proceeds from Company sponsored Initial Public Offering	$ 126,500,000	$ 126,500,000	$ 0	$ 0
Cash and cash equivalents		213,759,000	35,424,000	79,550,000
Restricted cash		127,765,000	0	$ 0
Other assets		205,838,000	272,876,000
Assets		3,043,250,000	2,713,903,000
Liabilities		2,090,220,000	2,028,235,000
Variable Interest Entity, Primary Beneficiary
Variable Interest Entity [Line Items]
Cash and cash equivalents		1,798,000	551,000
Restricted cash		127,765,000	0
Other assets		722,000	0
Assets		130,285,000	551,000
Other Liabilities		24,000	1,000
Liabilities		$ 24,000	$ 1,000