Summary of Significant Accounting Policies - Schedule of Net Income (Loss) Per Common Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended								12 Months Ended
	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2017	Mar. 31, 2016	Mar. 31, 2015
Numerator:
Net income	$ (5,171)	$ 29,969	$ 6,992	$ (3,286)	$ (589)	$ 9,664	$ 11,229	$ (3,068)	$ 28,504	$ 17,236	$ 16,954
Denominator:
Weighted average shares outstanding for basic income per common share (in shares)									9,074	9,147	9,326
Effect of dilutive stock options (in shares)									41	92	84
Adjusted weighted average shares outstanding for diluted income per common share (in shares)									9,115	9,239	9,410
Basic net income per common share (in dollars per share)	$ (0.57)	$ 3.30	$ 0.77	$ (0.36)	$ (0.06)	$ 1.07	$ 1.23	$ (0.33)	$ 3.14	$ 1.88	$ 1.82
Diluted net income per common share (in dollars per share)	$ (0.57)	$ 3.29	$ 0.77	$ (0.36)	$ (0.06)	$ 1.06	$ 1.22	$ (0.33)	$ 3.13	$ 1.87	$ 1.80