Credit Agreement (Details) (USD $)	6 Months Ended				1 Months Ended
	Sep. 30, 2014 Mortgage	Jul. 31, 2014 Mortgage	Sep. 30, 2014 Revolving Credit Facility Line of Credit Credit Agreement	Sep. 30, 2014 Revolving Credit Facility Line of Credit China Credit Agreement	Nov. 10, 2014 Revolving Credit Facility Subsequent Event Line of Credit Credit Agreement	Nov. 10, 2014 Revolving Credit Facility Subsequent Event Line of Credit China Credit Agreement
Notes Payable and Long-Term Debt
Outstanding borrowings			$ 146,000,000	$ 8,100,000	$ 182,000,000	$ 4,900,000
Outstanding letters of credit			100,000
Line of Credit Facility, Remaining Borrowing Capacity			253,900,000
Current borrowing capacity			231,200,000
Increase in borrowings					49,000,000
Repayments of Lines of Credit					13,000,000	3,200,000
Effective interest rate on debt	4.928%			6.00%
Debt Instrument, Face Amount		33,900,000
Gross amount of mortgage	33,900,000
Loan amortization period	30 years
Debt Instrument, Term for Minimum Payments	5 years
Debt Instrument, Periodic Payment	2,700,000
Term of mortgage loan	15 years
Debt Instrument, Periodic Payment Terms, Balloon Payment to be Paid	$ 23,400,000
Asset coverage ratio per debt covenant	1.10
Debt covenant ratio for earnings, EBITDA, and annual rental expense	2.25