Acquisitions (Details) - USD ($)	3 Months Ended		6 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015	Mar. 31, 2016
Business Acquisition [Line Items]
Net income	$ 6,816,000	$ (448,000)	$ 13,217,000	$ 6,463,000
Goodwill	170,404,000		170,404,000		$ 170,716,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Finite-Lived Intangibles	$ 677,000		677,000
Business Acquisition, Pro Forma Net Income (Loss)		$ 4,098,000	$ 13,217,000	$ 11,762,000
Basic income (loss) per share:	$ 0.34	$ (0.02)	$ 0.66	$ 0.32
Business Acquisition, Pro Forma Earnings Per Share, Basic		0.20		0.59
Diluted income (loss) per share:	$ 0.33	(0.02)	$ 0.65	0.32
Business Acquisition, Pro Forma Earnings Per Share, Diluted		$ 0.20		$ 0.58
Magnetek [Member]
Business Acquisition [Line Items]
Business Acquisition, Pro Forma Revenue		$ 163,902,000		$ 326,461,000