Loans Receivable - Outstanding Principal Balance and Related Carrying Value of Acquired Loans (Details) $ in Thousands	Dec. 31, 2019 USD ($)
Acquired
Accounts, Notes, Loans and Financing Receivable [Line Items]
Outstanding principal balance	$ 833,599
Carrying value	821,617
Acquired loans evaluated individually for future credit losses
Accounts, Notes, Loans and Financing Receivable [Line Items]
Outstanding principal balance	7,187
Carrying value	4,975
Acquired loans evaluated collectively for future credit losses
Accounts, Notes, Loans and Financing Receivable [Line Items]
Outstanding principal balance	826,412
Carrying value	$ 816,642