Annual report pursuant to Section 13 and 15(d)

Nature of Operations and Summary of Significant Accounting Policies - Narrative (Details)

v3.8.0.1
Nature of Operations and Summary of Significant Accounting Policies - Narrative (Details)
¥ in Millions
 3 Months Ended 12 Months Ended
Mar. 31, 2017
USD ($)
Dec. 31, 2017
USD ($)
installment
Dec. 31, 2016
USD ($)
installment
Dec. 31, 2015
USD ($)
Jun. 30, 2015
CNY (¥)
Property, Plant and Equipment [Line Items]          
Restricted cash | $   $ 3,100,000      
Loss on foreign exchange | $ $ (451,000)   $ (333,000) $ (204,000)  
Long-Term Incentive Plan, Payment Commencing in February of the Calendar Year Immediately Following the Conclusion of the Performance Period          
Property, Plant and Equipment [Line Items]          
Long-term incentive plan, percentage of award payable in cash   50.00%      
Long-term incentive plan, number of installments | installment   35      
Long-Term Incentive Plan, Payment Commencing in February 2021 and Ending in December 2023          
Property, Plant and Equipment [Line Items]          
Long-term incentive plan, percentage of award payable in cash     50.00%    
Long-term incentive plan, number of installments | installment     35    
Software and Software Development Costs [Member] | Minimum          
Property, Plant and Equipment [Line Items]          
Property, and equipment useful life   3 years      
Software and Software Development Costs [Member] | Maximum          
Property, Plant and Equipment [Line Items]          
Property, and equipment useful life 5 years        
Furniture and Fixtures | Minimum          
Property, Plant and Equipment [Line Items]          
Property, and equipment useful life   5 years      
Furniture and Fixtures | Maximum          
Property, Plant and Equipment [Line Items]          
Property, and equipment useful life   7 years      
China          
Property, Plant and Equipment [Line Items]          
Restricted cash | ¥         ¥ 20