Goodwill and Intangible Assets - Additional Information (Details)	3 Months Ended		12 Months Ended
	Mar. 31, 2017 USD ($) acquisition	Mar. 31, 2016 USD ($)	Dec. 31, 2016 USD ($)
Goodwill and Intangible Assets Disclosure [Abstract]
Number of acquisitions resulting in goodwill | acquisition	4
Business Acquisition [Line Items]
Goodwill impairment loss	$ 0		$ 0
Number of acquisitions resulting in core deposit intangible assets | acquisition	2
Intangible asset amortization	$ 60,000	$ 49,000
United American Savings Bank
Business Acquisition [Line Items]
Goodwill			6,600,000
Intangible asset amortization			$ 31,000