Acquisitions (Details) - USD ($)	12 Months Ended
	Mar. 31, 2017	Mar. 31, 2016	Mar. 31, 2015
Business Acquisition [Line Items]
Business Acquisition, Pro Forma Revenue	$ 777,847,000	$ 826,653,000
Goodwill	319,299,000	170,716,000	$ 121,461,000
Total purchase consideration	182,467,000
Deferred Tax Assets, Net	33,168,000	73,099,000
Business Acquisition, Pro Forma Net Income (Loss)	$ 20,699,000	$ 29,617,000
Business Acquisition, Pro Forma Earnings Per Share, Basic	$ 0.92	$ 1.33
Business Acquisition, Pro Forma Earnings Per Share, Diluted	$ 0.91	$ 1.31
Ergomatic Products LLC [Member]
Business Acquisition [Line Items]
Working capital	$ 212,000
Property, plant and equipment	246,000
Identifiable intangible assets	717,000
Total purchase consideration	1,175,000
Total purchase consideration	1,175,000
STB [Member]
Business Acquisition [Line Items]
Annual sales of acquired entity	16,000,000
STAHL [Member]
Business Acquisition [Line Items]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Cash and Equivalents	30,473,000
Working capital	18,593,000
Property, plant and equipment	14,234,000
Total purchase consideration	248,729,000
Intangible Assets, Gross (Excluding Goodwill)	143,039,000
Long-Lived Assets	380,000
Liabilities, Other than Long-term Debt, Noncurrent	(74,762,000)
Deferred Tax Assets, Net	(33,550,000)
Magnetek Acquisition [Member]
Business Acquisition [Line Items]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Cash and Equivalents	8,205,000
Working capital	19,660,000
Property, plant and equipment	5,660,000
Goodwill	49,204,000
Total purchase consideration	190,672,000
Intangible Assets, Gross (Excluding Goodwill)	105,998,000
Long-Lived Assets	3,921,000
Liabilities, Other than Long-term Debt, Noncurrent	(44,052,000)
Deferred Tax Assets, Net	$ 42,076,000