Fair Value - Assets and Liabilities Measured at Fair Value on Non-Recurring Basis (Details) - Fair Value, Measurements, Nonrecurring - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Commercial, industrial and agricultural
Impaired loans:
Assets, fair value disclosure	$ 5,627	$ 2,910
Commercial, industrial and agricultural | Quoted Prices in Active Markets for Identical Assets
Impaired loans:
Assets, fair value disclosure	0	0
Commercial, industrial and agricultural | Significant Other Observable Inputs
Impaired loans:
Assets, fair value disclosure	0	0
Commercial, industrial and agricultural | Significant Unobservable Inputs
Impaired loans:
Assets, fair value disclosure	5,627	2,910
Commercial mortgages
Impaired loans:
Assets, fair value disclosure	10,909	1,147
Commercial mortgages | Quoted Prices in Active Markets for Identical Assets
Impaired loans:
Assets, fair value disclosure	0	0
Commercial mortgages | Significant Other Observable Inputs
Impaired loans:
Assets, fair value disclosure	0	0
Commercial mortgages | Significant Unobservable Inputs
Impaired loans:
Assets, fair value disclosure	$ 10,909	$ 1,147