v3.8.0.1
Organization and Summary of Significant Accounting Policies - Narrative - Revenue Recognition (Details)
12 Months Ended
Dec. 31, 2017
Revenue Recognition, Multiple-deliverable Arrangements [Line Items]  
Period of time average selling prices are observed to establish best estimate of selling price 12 months
Minimum [Member]  
Revenue Recognition, Multiple-deliverable Arrangements [Line Items]  
Product or service delivery period 3 months
Maximum [Member]  
Revenue Recognition, Multiple-deliverable Arrangements [Line Items]  
Product or service delivery period 6 months