Fair Value Measurement - Nonrecurring (Details) - USD ($) $ in Thousands	3 Months Ended		12 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Dec. 31, 2019
Balances of the assets and liabilities measured at fair value on a nonrecurring basis
Loss	$ 2,100	$ 600
Nonrecurring
Balances of the assets and liabilities measured at fair value on a nonrecurring basis
Loss	49		$ 206
Nonrecurring | Impaired Loans
Balances of the assets and liabilities measured at fair value on a nonrecurring basis
Loss	49		206
Level 2 | Nonrecurring
Balances of the assets and liabilities measured at fair value on a nonrecurring basis
Assets measured at fair value	75		75
Level 2 | Nonrecurring | Impaired Loans
Balances of the assets and liabilities measured at fair value on a nonrecurring basis
Assets measured at fair value	$ 75		$ 75