Debt (Narratives) (Details) - USD ($)	9 Months Ended	12 Months Ended
	Dec. 31, 2016	Mar. 31, 2017	Mar. 31, 2016	Mar. 31, 2015	Jan. 31, 2017	Oct. 19, 2012
Line of Credit Facility [Line Items]
Outstanding letters of credit		$ 6,486,000
Payments of financing costs		(19,409,000)	$ 0	$ (1,825,000)
Carrying amount of the Company's revolving credit facility		432,500,000	112,500,000	103,125,000
Gain (Loss) on Extinguishment of Debt		(1,303,000)	0	$ (8,567,000)
New Senior Subordinated note issued		445,000,000
Secured Long-term Debt, Noncurrent		432,500,000	112,056,000
Secured Debt, Current		9,375,000
Gross balance of deferred costs		14,690,000	2,076,000
Accumulated amortization balances		350,000	483,000
Capital lease obligations		551,000	1,590,000
Debt obligations		4,475,000
Amount drawn on unsecured credit lines		0
Minimum
Line of Credit Facility [Line Items]
New Revolving Credit Facility maximum capacity						$ 225,000,000
Outstanding letters of credit		$ 492,000
Capital Lease Obligations
Line of Credit Facility [Line Items]
Term under lease agreement		10 years
Foreign Line of Credit
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity		$ 10,175,000
Outstanding borrowings		3,813,000
New Revolving Credit Facility | Line of Credit
Line of Credit Facility [Line Items]
Debt Instrument, Unamortized Discount		$ 444,000	558,000
New Revolving Credit Facility | Line of Credit | LIBOR
Line of Credit Facility [Line Items]
Basis points spread						1.00%
New Revolving Credit Facility | Line of Credit | Federal Funds Rate
Line of Credit Facility [Line Items]
Basis points spread						0.50%
New Debt | Minimum
Line of Credit Facility [Line Items]
Stated interest rate percentage						7.875%
STAHL China Loan [Member]
Line of Credit Facility [Line Items]
Stated interest rate percentage		4.00%
New Senior Subordinated note issued		$ 2,608,000
Replaced Revolving Credit [Member]
Line of Credit Facility [Line Items]
Revolving credit facility secured by Non US Subsidiary Stock	13150000000.00%
Gross balance of deferred costs		763,000	1,574,000
Other Current Liabilities [Member]
Line of Credit Facility [Line Items]
Capital lease obligations		510,000
Standby Letters of Credit
Line of Credit Facility [Line Items]
Outstanding letters of credit		5,994,000
STAHL [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity		100,000,000			$ 545,000,000
Repayments of Lines of Credit		12,500,000
Secured Debt, Current		4,450,000
STAHL [Member] | Line of Credit
Line of Credit Facility [Line Items]
Secured Long-term Debt, Noncurrent		445,000,000
STAHL [Member] | New Revolving Credit Facility
Line of Credit Facility [Line Items]
Secured Long-term Debt, Noncurrent		100,000,000
Gross balance of deferred costs		2,789,000
Accumulated amortization balances		93,000
STAHL [Member] | Other Current Liabilities [Member]
Line of Credit Facility [Line Items]
Secured Long-term Debt, Noncurrent		49,450,000
Magnetek [Member] | Replaced Revolving Credit [Member]
Line of Credit Facility [Line Items]
Accumulated amortization balances			367,000
Magnetek [Member] | Other Current Liabilities [Member]
Line of Credit Facility [Line Items]
Secured Long-term Debt, Noncurrent		$ 12,500,000
ASU 2015_03 Retrospective Reclass [Member]
Line of Credit Facility [Line Items]
Gross balance of deferred costs			$ 193,000