Fair Value - Narrative (Details) - USD ($) $ in Thousands	3 Months Ended		12 Months Ended
	Mar. 31, 2017	Mar. 31, 2016	Dec. 31, 2016
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired loans	$ 8,858		$ 2,887
Outstanding balance of impaired loans	9,194		3,082
Related Allowance	2,542		1,133
Provision	0	$ 300
Other real estate owned, net	4,911		5,042
Fair value measurements
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and cash equivalents	31,237		22,507
Fair value measurements | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and cash equivalents	31,237		22,507
Impaired financing receivable, recent appraisal
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impaired loans	5,000		200
Outstanding balance of impaired loans	7,000		800
Related Allowance	2,000		600
Provision	1,500		600
Other real estate, recent appraisal
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other real estate owned, net	700		2,500
Real estate acquired, outstanding balance of related loan	1,300		3,700
Valuation allowance of real estate owned	600
Local school district bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Local school district bonds	$ 2,700		$ 2,700