COVID-19 (Details) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020 USD ($) loan	Sep. 30, 2019 USD ($) loan	Sep. 30, 2020 USD ($) loan	Sep. 30, 2019 USD ($) loan
Unusual or Infrequent Item, or Both [Line Items]
Financing receivable, approved modifications, number of loans | loan		0	2	0
Provision for (reversal of) loan losses	$ 0	$ (500)	$ 10,550	$ 250
COVID-19
Unusual or Infrequent Item, or Both [Line Items]
Financing receivable, approved modifications, number of loans | loan			269
Financing receivable, approved modifications, percent	6.50%		6.50%
Financing receivable, modifications, returned to payment status, number of loans | loan	222		222
Financing receivable, modifications, returned to payment status, amount	$ 322,100		$ 322,100
Financing receivable, modifications, paid off, number of loans | loan	15		15
Financing receivable, modifications, paid off, amount	$ 24,000		$ 24,000
Provision for (reversal of) loan losses			10,200
Financing receivable, modifications, amount	$ 397,500		$ 397,500