Stock Transactions and Unit Redemptions - Gross Unit Redemptions and Share Repurchases of Class A Common Stock (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	1 Months Ended	3 Months Ended
Mar. 31, 2021	Feb. 28, 2021	Mar. 31, 2021
Stock Transactions Parenthetical Disclosures [Abstract]
Redemptions, Number of Units			20
Repurchases, Number of Shares	3	962	965
Total Number of Units Redeemed or Shares Repurchased			985
Redemptions, Weighted Average Price Paid per Unit or Share			$ 4.40
Repurchases, Weighted Average Price Paid per Unit or Shares	$ 4.29	$ 4.56	4.56
Total Redemptions and Repurchases, Weighted Average Price Paid per Unit or Shares			$ 4.56
Total Redemptions and Repurchases, Approximate Dollar Value of Units and Shares That May Yet Be Redeemed/Purchased Under the Program	$ 245,422		$ 245,422

Number of shares that have been repurchased during the period and are being held in treasury.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=109259400&loc=d3e21463-112644

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.3-04)
-URI http://asc.fasb.org/extlink&oid=120397183&loc=d3e187085-122770

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(29))
-URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

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