Acquisitions - Schedule of Acquisition Price Allocation (Parenthetical) (Detail) - USD ($) $ / shares in Units, $ in Millions		3 Months Ended		9 Months Ended
	Jul. 02, 2020	Sep. 30, 2020	Mar. 31, 2019	Sep. 30, 2020	Jul. 01, 2020
Business Acquisition [Line Items]
Intangible assets, weighted average useful life				4 years 8 months 12 days
Peak [Member]
Business Acquisition [Line Items]
Intangible assets, weighted average useful life	5 years 4 months 24 days
Contingent consideration obligation	$ 23.8				$ 23.8
Discount rate related to deferred consideration	4.90%
Class A Common stock [Member]
Business Acquisition [Line Items]
Consideration transferred by issue of shares		116,564,000	63,795,000
Class A Common stock [Member] | Peak [Member]
Business Acquisition [Line Items]
Consideration transferred by issue of shares	116,564,861
Shares issued, price per share	$ 9.76
Developed Technology, Useful Life of 5 Years [Member] | Peak [Member]
Business Acquisition [Line Items]
Intangible assets, useful life	5 years
Trade Names, Useful Life of 7 Years [Member] | Peak [Member]
Business Acquisition [Line Items]
Intangible assets, useful life	7 years
Domain Names Weighted Average Useful Life of 14 years [Member] | Peak [Member]
Business Acquisition [Line Items]
Intangible assets, weighted average useful life	14 years