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Selected Balance Sheet Data - Schedule of Other Assets (Detail) - USD ($) $ in Thousands | Sep. 30, 2019 | Dec. 31, 2018
--- | --- | ---
Other Assets [Line Items] |  |
Other assets Current | $ 12,352 | $ 6,368
Other assets Non-Current | 53,432 | 31,778
Mortgage servicing rights [Member] |  |
Other Assets [Line Items] |  |
Other assets Current | 0 | 0
Other assets Non-Current | 2,039 | 2,209
Due from independent contractors, net [Member] |  |
Other Assets [Line Items] |  |
Other assets Current | 2,381 | 3,831
Other assets Non-Current | 48,911 | 27,157
Security deposits [Member] |  |
Other Assets [Line Items] |  |
Other assets Current | 0 | 0
Other assets Non-Current | 1,313 | 1,196
Employee Notes Receivable [Member] |  |
Other Assets [Line Items] |  |
Other assets Current | 150 | 156
Other assets Non-Current | 373 | 370
Customer trust accounts and other [Member] |  |
Other Assets [Line Items] |  |
Other assets Current | 9,821 | 2,381
Other assets Non-Current | $ 796 | $ 846

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