Debt (Details) - USD ($)	3 Months Ended	12 Months Ended
	Mar. 31, 2018	Mar. 31, 2019
Debt Instrument [Line Items]
Debt Instrument, Term		7 years
Line of Credit Facility, Expiration Period		5 years
Capital lease obligations	$ 98,000	$ 0
Total senior debt	98,000	0
Long-term Debt, Gross	375,463,000	310,463,000
Outstanding borrowings	(12,243,000)	(10,143,000)
Long-term Debt	363,318,000	300,320,000
Current portion of long-term debt	60,064,000	65,000,000
Long-term Debt, Excluding Current Maturities	303,254,000	235,320,000
Maturities of Long-term Debt [Abstract]
2015		4,450,000
2016		4,450,000
2017		4,450,000
2018		4,450,000
2019		292,663,000
Thereafter		0
Other Current Liabilities [Member]
Debt Instrument [Line Items]
Debt Instrument, Periodic Payment, Principal	$ 57,037,000
STAHL [Member] | Other Current Liabilities [Member]
Debt Instrument [Line Items]
Debt Instrument, Periodic Payment, Principal		$ 65,000,000