Major Customers (Details) - customer |
12 Months Ended | ||
|---|---|---|---|
Dec. 31, 2017 |
Dec. 31, 2016 |
Dec. 31, 2015 |
|
| Major Customers | |||
| Revenue as a percentage of the company's total | 22.00% | 19.00% | 18.00% |
| Revenues | Customer concentration risk | Fidelity | |||
| Major Customers | |||
| Number of customers accounted for as major customer | 1 | 1 | 1 |
| Revenue as a percentage of the company's total | 17.00% | 15.00% | 18.00% |
| X | ||||||||||
- Definition Represents the number of customers of the entity. No definition available.
|
| X | ||||||||||
- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. No definition available.
|
| X | ||||||||||
- Definition For an entity that discloses a concentration risk in relation to quantitative amount, which serves as the "benchmark" (or denominator) in the equation, this concept represents the concentration percentage derived from the division. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- Details
|
| X | ||||||||||
- Details
|
| X | ||||||||||
- Details
|