Mergers and Acquisitions - Additional Information (Details) - USD ($) $ / shares in Units, $ in Thousands		3 Months Ended		12 Months Ended
	Apr. 30, 2016	Mar. 31, 2017	Mar. 31, 2016	Dec. 31, 2016	Dec. 31, 2015
Business Acquisition [Line Items]
Total assets		$ 706,317		$ 692,135
Goodwill		10,288		10,288
Amortization		60	$ 49
United American Savings Bank
Business Acquisition [Line Items]
Payments to acquire businesses, gross	$ 13,200
Acquisition share price (in dollars per share)	$ 42.67
Goodwill	$ 6,624
Core deposit intangible	232
Amortization				$ 31
Finite-Lived Intangible Assets, Amortization Expense, Maturity Schedule [Abstract]
2017		40
2018		32
2019		26
2020		20
After 2020		$ 83
Loans receivable	66,145
Credit-related adjustment	927
Adjustment for other factors	$ 982
Acquisition related costs			309
United American Savings Bank | Legal Fees
Finite-Lived Intangible Assets, Amortization Expense, Maturity Schedule [Abstract]
Acquisition related costs			144
United American Savings Bank | System Conversion Costs
Finite-Lived Intangible Assets, Amortization Expense, Maturity Schedule [Abstract]
Acquisition related costs			100
United American Savings Bank | Other Professional Fees
Finite-Lived Intangible Assets, Amortization Expense, Maturity Schedule [Abstract]
Acquisition related costs			$ 65
United American Savings Bank | Core Deposits
Business Acquisition [Line Items]
Weighted average useful life	10 years
United American Savings Bank
Business Acquisition [Line Items]
Total assets					$ 89,300