Annual report pursuant to Section 13 and 15(d)

Commitments and Contingencies - Additional Information (Detail)

v3.8.0.1
Commitments and Contingencies - Additional Information (Detail) - USD ($)
1 Months Ended 12 Months Ended
May 31, 2015
Dec. 31, 2017
Dec. 31, 2016
Dec. 31, 2015
Loss Contingencies [Line Items]        
Rent expense   $ 13,800,000 $ 14,700,000 $ 10,900,000
Richardson, Texas | Office Space        
Loss Contingencies [Line Items]        
Term of lease (in years) 12 years      
Indemnification Agreement        
Loss Contingencies [Line Items]        
Guarantor obligations, current carrying value   $ 0 $ 0