Quarterly report pursuant to Section 13 or 15(d)

Property, Equipment and Software - Additional Information (Details)

v3.7.0.1
Property, Equipment and Software - Additional Information (Details) - USD ($)
$ in Millions
3 Months Ended 6 Months Ended
Jun. 30, 2017
Jun. 30, 2016
Jun. 30, 2017
Jun. 30, 2016
Dec. 31, 2016
Property, Plant and Equipment [Line Items]          
Depreciation and amortization expense for property, equipment and software $ 6.9 $ 6.5 $ 13.5 $ 11.9  
Carrying amount of capitalized software development costs 63.9   63.9   $ 55.4
Accumulated depreciation of capitalized software development costs (23.2)   (23.2)   $ (19.8)
Software          
Property, Plant and Equipment [Line Items]          
Depreciation and amortization expense for property, equipment and software $ 1.8 $ 1.4 $ 3.4 $ 2.6