Stock-Based Compensation - Assumptions and Activity (Details) - USD ($)	6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016
Weighted Average Exercise Price
Aggregate intrinsic value of all options outstanding	$ 1,000
Aggregate intrinsic value of all options exercisable	$ 0
Stock Options.
Assumptions used to determine fair value of stock options granted
Dividend yield (as a percent)	0.00%	0.00%
Expected volatility (as a percent)	41.30%	42.40%
Expected life of option	5 years	5 years
Risk-free interest rate (as a percent)	1.80%	1.30%
Fair value of each option on grant date (in dollars per share)	$ 3.43	$ 4.02
Shares
Outstanding at beginning of period (in shares)	16,168
Granted (in shares)	2,250	4,500
Exercised (in shares)	(250)	(500)
Outstanding at end of period (in shares)	18,168
Exercisable at end of period (in shares)	10,499
Weighted Average Exercise Price
Outstanding at beginning of period (in dollars per shares)	$ 14.40
Granted (in dollars per share)	8.91
Exercised (in dollars per share)	7.54
Outstanding at end of period (in dollars per share)	13.81
Exercisable at end of period (in dollars per share)	$ 15.41