Credit Agreement (Details) (USD $)			1 Months Ended
	Mar. 31, 2014 Credit Agreement	Mar. 31, 2014 China Credit Agreement	May 12, 2014 China Credit Agreement Subsequent Event
Notes Payable and Long-Term Debt
Outstanding borrowings	$ 0	$ 6,700,000	$ 3,200,000
Outstanding letters of credit	100,000
Amount unused balance under the Credit Agreement	399,900,000
Current borrowing capacity	172,800,000
Effective interest rate on debt		6.00%
Repaid on borrowings			$ 3,500,000