Employee Stock Ownership Plan - Loan, Expense and Shares (Details) - USD ($) $ / shares in Units, $ in Thousands		12 Months Ended
	Jul. 10, 2009	Dec. 31, 2019	Dec. 31, 2018
Employee Stock Ownership Plan
Allocated shares		466,807	446,041
Unearned shares		440,397	489,329
Total ESOP shares		907,204	935,370
Fair value of unearned shares, in thousands		$ 13,626	$ 12,713
ESOP
Employee Stock Ownership Plan
Amount borrowed from employer	$ 9,800
Shares purchased	978,650
Percentage of shares issued in initial public offering	8.00%
Employee stock ownership plan, price per share of shares acquired in initial public offering (in dollars per share)	$ 10.00
Term of loan		20 years
ESOP expense		$ 1,400	$ 1,500
ESOP | Prime rate
Employee Stock Ownership Plan
Variable interest rate		prime rate, as published in The Wall Street Journal