Equity Compensation Plans - Restricted Stock and RSUs (Details) - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Equity Compensation Plans
Vesting period	3 years
Restricted stock and restricted stock units
Changes in unvested awards
Nonvested at the beginning of the period (in shares)	348,000
Granted (in shares)	170,000	101,500
Vested (in shares)	(105,500)
Forfeited (in shares)	(3,500)
Nonvested at the end of the period (in shares)	409,000	348,000
Weighted Average Grant Date Fair Value
Nonvested at the beginning of the period (in dollars per share)	$ 4.50
Granted (in dollars per share)	7.14
Vested (in dollars per share)	3.28
Forfeited (in dollars per share)	6.81
Nonvested at the end of the period (in dollars per share)	$ 5.89	$ 4.50
Additional information
Total unrecognized compensation cost of restricted awards	$ 1.2
Expected weighted-average period for recognition of unrecognized compensation	2 years 2 months 19 days