Related Party Transactions - Service Provider (Details) - USD ($) $ in Thousands |
12 Months Ended | ||
|---|---|---|---|
Dec. 31, 2015 |
Dec. 31, 2014 |
Dec. 31, 2013 |
|
| Related Party Transaction [Line Items] | |||
| Prepaid expense relating to marketing firm | $ 6,048 | $ 5,193 | |
| Marketing Firm With Related Officer | |||
| Related Party Transaction [Line Items] | |||
| Prepaid expense relating to marketing firm | 900 | ||
| Amounts due to marketing firm | 200 | ||
| Marketing Firm With Related Officer | Selling and Marketing Expense | |||
| Related Party Transaction [Line Items] | |||
| Sales and marketing expense | $ 6,800 | $ 4,200 | $ 1,100 |