Amount of cash and cash equivalents restricted as to withdrawal or usage, classified as noncurrent. Cash includes, but is not limited to, currency on hand, demand deposits with banks or financial institutions, and other accounts with general characteristics of demand deposits. Cash equivalents include, but are not limited to, short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates.

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Name:	us-gaap_RestrictedCashAndCashEquivalentsNoncurrent
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

Leases - Schedule of Description of Operating Lease (Parenthetical) (Detail) $ in Millions	Mar. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)	Aug. 31, 2019 USD ($) RenewalOption	May 31, 2018 USD ($)
Leases [Line Items]
Restricted cash	$ 3.2	$ 3.2
12780/90 El Camino Real Lease Agreement
Leases [Line Items]
Number of times to renew the lease contract \| RenewalOption			2
Lease extension period			10 years
12780/90 El Camino Real Lease Agreement \| Letter of Credit
Leases [Line Items]
Restricted cash			$ 3.0
12777 High Bluff Drive Lease Agreement \| Letter of Credit
Leases [Line Items]
Restricted cash		$ 0.2		$ 1.0