Internal-Use Software - Additional Information (Detail) - Early Adoption ASU 2018-15 [Member] - USD ($) $ in Millions	3 Months Ended	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2019	Dec. 31, 2018
Deferred Costs Capitalized Prepaid And Other Assets Disclosure [Line Items]
Capitalized implementation costs net of amortizations, for software services	$ 13.8	$ 13.8	$ 10.6
Capitalized implementation costs during the period	$ 2.0	$ 3.6
Minimum [Member]
Deferred Costs Capitalized Prepaid And Other Assets Disclosure [Line Items]
Capitalized implementation costs amortization period		3 years
Maximum [Member]
Deferred Costs Capitalized Prepaid And Other Assets Disclosure [Line Items]
Capitalized implementation costs amortization period		10 years