| Selected Balance Sheet Data - Schedule of Other Assets (Detail) - USD ($) $ in Thousands | Jun. 30, 2016 | Dec. 31, 2015 | 
|---|---|---|
| Other Assets [Line Items] | ||
| Other assets Current | $ 4,938 | $ 5,136 | 
| Other assets Non-Current | 9,657 | 9,116 | 
| Due from independent contractors [Member] | ||
| Other Assets [Line Items] | ||
| Other assets Current | 1,857 | 2,545 | 
| Other assets Non-Current | 8,142 | 7,358 | 
| Security deposits [Member] | ||
| Other Assets [Line Items] | ||
| Other assets Current | 0 | 0 | 
| Other assets Non-Current | 1,073 | 1,425 | 
| Employee Notes Receivable [Member] | ||
| Other Assets [Line Items] | ||
| Other assets Current | 364 | 224 | 
| Other assets Non-Current | 112 | 158 | 
| Customer trust accounts and other [Member] | ||
| Other Assets [Line Items] | ||
| Other assets Current | 2,717 | 2,367 | 
| Other assets Non-Current | $ 330 | $ 175 | 
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- Definition Other Assets [Line Items] No definition available. 
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- Definition Amount of current assets classified as other. Reference 1: http://www.xbrl.org/2003/role/presentationRef 
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