Unaudited Quarterly Financial Data (Details) (USD $)	3 Months Ended								12 Months Ended
	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2014	Mar. 31, 2013	Mar. 31, 2012
Unaudited Quarterly Financial Data [Abstract]
Net sales	$ 76,682,000	$ 65,568,000	$ 66,174,000	$ 50,245,000	$ 58,042,000	$ 50,658,000	$ 57,652,000	$ 46,799,000	$ 258,669,000	$ 213,151,000	$ 178,551,000
Cost of goods sold	52,761,000	43,642,000	46,469,000	34,231,000	39,942,000	34,332,000	37,556,000	31,980,000	177,103,000	143,810,000	121,219,000
Gross profit	23,921,000	21,926,000	19,705,000	16,014,000	18,100,000	16,326,000	20,096,000	14,819,000	81,566,000	69,341,000	57,332,000
Operating expenses [Abstract]
General and administrative	11,766,000	9,580,000	8,706,000	9,632,000	6,653,000	8,848,000	4,392,000	5,914,000	39,684,000	25,807,000	20,621,000
Sales and marketing	2,059,000	1,905,000	2,143,000	1,731,000	1,811,000	1,983,000	1,724,000	1,772,000	7,838,000	7,290,000	7,659,000
Research and development	541,000	452,000	398,000	549,000	588,000	445,000	461,000	436,000	1,940,000	1,930,000	1,765,000
Total operating expenses	14,366,000	11,937,000	11,247,000	11,912,000	9,052,000	11,276,000	6,577,000	8,122,000	49,462,000	35,027,000	30,758,000
Operating income	9,555,000	9,989,000	8,458,000	4,102,000	9,048,000	5,050,000	13,519,000	6,697,000	32,104,000	34,314,000	26,574,000
Other expense [Abstract]
Interest expense, net	3,177,000	6,524,000	4,663,000	3,925,000	3,951,000	2,384,000	3,093,000	2,896,000	18,289,000	12,324,000	4,841,000
Income from continuing operations before income tax expense	6,378,000	3,465,000	3,795,000	177,000	5,097,000	2,666,000	10,426,000	3,801,000	13,815,000	21,990,000	21,733,000
Income tax expense	3,311,000	2,317,000	1,631,000	74,000	1,195,000	880,000	3,923,000	1,434,000	7,333,000	7,432,000	7,385,000
Income from continuing operations	3,067,000	1,148,000	2,164,000	103,000	3,902,000	1,786,000	6,503,000	2,367,000	6,482,000	14,558,000	14,348,000
Income (loss) from discontinued operations	0	0	0	100,877,000	(77,553,000)	(851,000)	(15,436,000)	(12,229,000)	100,877,000	(106,069,000)	(62,862,000)
Net income (loss)	$ 3,067,000	$ 1,148,000	$ 2,164,000	$ 100,980,000	$ (73,651,000)	$ 935,000	$ (8,933,000)	$ (9,862,000)	$ 107,359,000	$ (91,511,000)	$ (48,514,000)
Basic net income per share from continuing operations (in dollars per share)	$ 0.20	$ 0.08	$ 0.15	$ 0.01	$ 0.27	$ 0.12	$ 0.45	$ 0.17	$ 0.45	$ 1.01	$ 1.15
Basic net income (loss) per share from discontinued operations (in dollars per share)	$ 0	$ 0	$ 0	$ 6.97	$ (5.36)	$ (0.06)	$ (1.07)	$ (0.88)	$ 6.89	$ (7.40)	$ (5.05)
Basic net income (loss) per share (in dollars per share)	$ 0.20	$ 0.08	$ 0.15	$ 6.98	$ (5.09)	$ 0.06	$ (0.62)	$ (0.71)	$ 7.34	$ (6.39)	$ (3.90)
Diluted net income per share from continuing operations (in dollars per share)	$ 0.19	$ 0.07	$ 0.15	$ 0.01	$ 0.27	$ 0.12	$ 0.45	$ 0.17	$ 0.42	$ 1.01	$ 1.13
Diluted net income (loss) per share from discontinued operation (in dollars per share)	$ 0	$ 0	$ 0	$ 6.90	$ (5.35)	$ (0.06)	$ (1.07)	$ (0.87)	$ 6.59	$ (7.37)	$ (4.93)
Diluted net income (loss) per share (in dollars per share)	$ 0.19	$ 0.07	$ 0.15	$ 6.91	$ (5.08)	$ 0.06	$ (0.62)	$ (0.70)	$ 7.01	$ (6.36)	$ (3.80)