Revolving Credit Facility and Bank Borrowings (Revolving Credit Facilities and Notes Payable) (Details)	Mar. 31, 2017 USD ($)	Mar. 31, 2017 CNY (¥)	Dec. 31, 2016 USD ($)
Line of Credit Facility [Line Items]
Amount allowed for repurchase under Amendment	$ 118,700,000
Senior Revolving Credit Facility [Member]
Line of Credit Facility [Line Items]
Outstanding borrowing threshold for covenant restrictions	20,000,000
Outstanding letters of credit	$ 1,300,000
Enterprise Software System Financing [Member] | Minimum [Member] | Notes Payable [Member]
Line of Credit Facility [Line Items]
Notes payable stated interest rate (percent)	1.99%	1.99%
Enterprise Software System Financing [Member] | Maximum [Member] | Notes Payable [Member]
Line of Credit Facility [Line Items]
Notes payable stated interest rate (percent)	2.63%	2.63%
Revolving Credit Facility [Member] | Senior Revolving Credit Facility [Member]
Line of Credit Facility [Line Items]
Current borrowing capacity	$ 80,000,000
Amount allowed for repurchase under Amendment	50,000,000
Maximum capital expenditures and commitments	$ 50,000,000
Minimum fixed charge coverage ratio	110.00%	110.00%
Leverage ratio	200.00%	200.00%
Weighted average Interest rate (percent)	3.54%	3.54%
Available borrowing capacity	$ 75,200,000		$ 78,700,000
Revolving Credit Facility [Member] | Asia Pacific Revolving Credit Facility [Member]
Line of Credit Facility [Line Items]
Current borrowing capacity	8,700,000	¥ 60,000,000
Revolving Loan Facility [Member] | Asia Pacific Revolving Credit Facility [Member]
Line of Credit Facility [Line Items]
Current borrowing capacity	$ 5,800,000	¥ 40,000,000