Property and Equipment, Net (Details) - USD ($) $ in Thousands |
Dec. 31, 2016 |
Dec. 31, 2015 |
|---|---|---|
| Summary of Property and equipment, net [Abstract] | ||
| Property and equipment, gross | $ 215,380 | $ 211,529 |
| Less accumulated depreciation and amortization | 149,011 | 137,576 |
| Property and equipment, net | 66,369 | 73,953 |
| Land [Member] | ||
| Summary of Property and equipment, net [Abstract] | ||
| Property and equipment, gross | 10,976 | 10,976 |
| Buildings and Leasehold Improvements [Member] | ||
| Summary of Property and equipment, net [Abstract] | ||
| Property and equipment, gross | 64,828 | 63,967 |
| Office Furniture and Equipment [Member] | ||
| Summary of Property and equipment, net [Abstract] | ||
| Property and equipment, gross | 24,234 | 22,869 |
| Computer Equipment and Software [Member] | ||
| Summary of Property and equipment, net [Abstract] | ||
| Property and equipment, gross | 114,749 | 113,223 |
| Automobiles [Member] | ||
| Summary of Property and equipment, net [Abstract] | ||
| Property and equipment, gross | $ 593 | $ 494 |