Summary of Significant Accounting Policies - Schedule of Estimated Useful Life of Intangible Assets (Detail)
|
12 Months Ended |
Dec. 31, 2017 |
|---|
| Minimum [Member] |
|
| Finite-Lived Intangible Assets [Line Items] |
|
| Intangible assets, Estimated useful life |
1 year 9 months
|
| Maximum [Member] |
|
| Finite-Lived Intangible Assets [Line Items] |
|
| Intangible assets, Estimated useful life |
15 years
|
| Trademarks [Member] | Minimum [Member] |
|
| Finite-Lived Intangible Assets [Line Items] |
|
| Intangible assets, Estimated useful life |
3 years
|
| Trademarks [Member] | Maximum [Member] |
|
| Finite-Lived Intangible Assets [Line Items] |
|
| Intangible assets, Estimated useful life |
15 years
|
| Customer Relationships [Member] |
|
| Finite-Lived Intangible Assets [Line Items] |
|
| Intangible assets, Estimated useful life |
5 years
|
| Websites [Member] |
|
| Finite-Lived Intangible Assets [Line Items] |
|
| Intangible assets, Estimated useful life |
4 years
|
| Domain Names [Member] | Minimum [Member] |
|
| Finite-Lived Intangible Assets [Line Items] |
|
| Intangible assets, Estimated useful life |
4 years
|
| Domain Names [Member] | Maximum [Member] |
|
| Finite-Lived Intangible Assets [Line Items] |
|
| Intangible assets, Estimated useful life |
10 years
|
| Licensing Agreements [Member] |
|
| Finite-Lived Intangible Assets [Line Items] |
|
| Intangible assets, Estimated useful life |
1 year 9 months
|
| Insurance Brokerage License [Member] |
|
| Finite-Lived Intangible Assets [Line Items] |
|
| Intangible assets, Estimated useful life |
4 years
|