Commitments and Contingencies - Allowance for Credit Losses for Unfunded Loan Commitments (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Jan. 01, 2020
Other Commitments [Line Items]
Balance at beginning of period	$ 3,112
Allowance for credit losses on unfunded loan commitments	6,077	$ 3,113
Provision for credit losses	1,616
Balance at end of period	6,077
Impact of ASU 2016-13 Adoption
Other Commitments [Line Items]
Balance at beginning of period	1,349
Allowance for credit losses on unfunded loan commitments	1,349	1,349
As Reported Under ASU 2016-13
Other Commitments [Line Items]
Balance at beginning of period	4,461
Allowance for credit losses on unfunded loan commitments	$ 4,461	$ 4,462