Equity and Share Based Payments - Deferred Stock Units (Details) - Deferred stock units $ / shares in Units, $ in Thousands	9 Months Ended
	Sep. 30, 2018 USD ($) $ / shares shares
Number of Shares
DSU's outstanding at beginning of year (in shares) | shares	100,750
DSU's exercised (in shares) | shares	62,917
DSU's forfeited / cancelled (in shares) | shares	13,333
DSU's outstanding at end of year (in shares) | shares	24,500
Weighted-Average Grant Date Fair Value
DSU's outstanding at beginning of year (in dollars per share) | $ / shares	$ 10.41
DSU's exercised (in dollars per share) | $ / shares	9.63
DSU's forfeited / cancelled (in dollars per share) | $ / shares	14.64
DSU's outstanding at end of year (in dollars per share) | $ / shares	$ 10.11
Additional information regarding DSUs
Unrecognized compensation cost | $	$ 44
Weighted-average period over which compensation cost is expected to be recognized	1 year 11 months 1 day