Summary of Significant Accounting Policies (Tables)
 12 Months Ended
Dec. 31, 2015
Accounting Policies [Abstract]  
Schedule of Customer Liabilities
 
 
December 31,
 
 
2015
 
2014
Deferred customer billings, current
 
$
130,124

 
$
132,063

Accrued service costs, current
 
70,656

 
68,077

Customer deposits, current
 
1,641

 
19,675

Deferred revenue, current
 
95

 
183

Current portion of customer liabilities
 
202,516

 
219,998

Deferred customer billings, non-current
 
431,944

 
317,065

Customer deposits, non-current
 
533

 
—

Non current portion of customer liabilities
 
432,477

 
317,065

Total customer liabilities
 
$
634,993

 
$
537,063
Assets Measured at Fair Value Categorized Using Fair Value Hierarchy
Activity in Allowance for Doubtful Accounts
Movements in the allowance for doubtful accounts are as follows (in thousands):
 
 
December 31,
 
 
2015
 
2014
 
2013
Beginning balance
 
$
314

 
$
740

 
$
183

Provision (recovery)
 
(46
)
 
(430
)
 
634

Write-offs
 
(169
)
 
4

 
(77
)
Ending balance
 
$
99

 
$
314

 
$
740
Property, Equipment and Software, Schedule of Useful Lives
The major classifications of property, equipment and software and their expected useful lives are as follows: 
Computers and other equipment
  
3 years
Leasehold improvements
  
Shorter of 10 years or lease term
Office furniture
  
5 years
Software
  
3 to 5 years