Fair Value Measurements, Fair Value Measured On a Nonrecurring Basis (Details) - Fair Value, Measurements, Nonrecurring [Member] - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Impaired Loans [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Gross charge-offs against allowance for loan losses	$ 9,581	$ 497
Net losses and expenses of repossessed assets, net	0	0
Real estate and other repossessed assets [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Gross charge-offs against allowance for loan losses	0	0
Net losses and expenses of repossessed assets, net	434	5,192
Fair Value, Inputs, Level 1 [Member] | Impaired Loans [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure	0	0
Fair Value, Inputs, Level 1 [Member] | Real estate and other repossessed assets [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure	0	0
Fair Value, Inputs, Level 2 [Member] | Impaired Loans [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure	0	32
Fair Value, Inputs, Level 2 [Member] | Real estate and other repossessed assets [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure	2,688	863
Fair Value, Inputs, Level 3 [Member] | Impaired Loans [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure	9,712	410
Fair Value, Inputs, Level 3 [Member] | Real estate and other repossessed assets [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure	$ 144	$ 7,094