Quarterly Financial Data (Unaudited) (Details) - USD ($) $ / shares in Units, $ 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
Quarterly Financial Data (Unaudited)
Net sales	$ 58,669	$ 117,153	$ 101,291	$ 45,318	$ 56,744	$ 104,568	$ 111,477	$ 44,228	$ 322,431	$ 317,017	$ 313,044
Gross profit	12,214	36,978	31,600	12,297	16,850	35,188	37,791	12,442
Net (loss) income	$ (5,171)	$ 29,969	$ 6,992	$ (3,286)	$ (589)	$ 9,664	$ 11,229	$ (3,068)	$ 28,504	$ 17,236	$ 16,954
Net (loss) income per common share:
Basic (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 (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