Goodwill and Intangible Assets (Details) - USD ($)	12 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Goodwill [Roll Forward]
Opening Balance	$ 170,716,000	$ 121,461,000
Acquisition of Hebetechnik (See Note 3)	(1,739,000)	1,720,000
Closing Balance	319,299,000	170,716,000
Gross Carrying Amount	279,197,000	137,687,000
Indefinite-lived trademark	46,018,000	29,006,000
Accumulated Amortization	(23,014,000)	(15,558,000)
Net	256,183,000	122,129,000
Trademark
Goodwill [Roll Forward]
Gross Carrying Amount	5,151,000	5,467,000
Accumulated Amortization	(2,616,000)	(2,431,000)
Net	2,535,000	3,036,000
Customer relationships
Goodwill [Roll Forward]
Gross Carrying Amount	177,983,000	58,535,000
Accumulated Amortization	(14,873,000)	(10,688,000)
Net	163,110,000	47,847,000
Acquired technology
Goodwill [Roll Forward]
Gross Carrying Amount	46,574,000	43,198,000
Accumulated Amortization	(4,603,000)	(1,873,000)
Net	41,971,000	41,325,000
Other
Goodwill [Roll Forward]
Gross Carrying Amount	3,471,000	1,481,000
Accumulated Amortization	(922,000)	(566,000)
Net	2,549,000	915,000
STB [Member]
Goodwill [Roll Forward]
Acquisition	170,716,000	(1,669,000)
Magnetek [Member]
Goodwill [Roll Forward]
Acquisition		$ 49,204,000
STAHL [Member]
Goodwill [Roll Forward]
Acquisition	150,322,000
Closing Balance	$ 150,322,000