|
Summary of Significant Accounting Policies - Summary of Depreciation Expenses on Internally Developed Software and Website Development Costs (Detail) (USD $)
In Thousands, unless otherwise specified |
3 Months Ended | |
|---|---|---|
|
Mar. 31, 2015
|
Mar. 31, 2014
|
|
| Depreciation and Other Amortization Expenses [Line Items] | ||
| Depreciation expense on internally developed software and website development costs | $ 5,145 | $ 3,763 |
| Internally Developed Software and Website Development Costs [Member] | ||
| Depreciation and Other Amortization Expenses [Line Items] | ||
| Depreciation expense on internally developed software and website development costs | $ 1,577 | $ 1,294 |