Supplemental Financial Information - Noncash Investing and Financing Activities (Parenthetical) (Detail) - shares	3 Months Ended
Mar. 31, 2020	Mar. 31, 2019
Restricted Stock [Member]
Condensed Financial Statements, Captions [Line Items]
Number of shares of common stock withheld	85,131	81,480

Number of shares used to settle grantee's tax withholding obligation for award under share-based payment arrangement.

No definition available.

Name:	us-gaap_SharesPaidForTaxWithholdingForShareBasedCompensation
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration