Related Party Transactions - Additional Information (Detail)	1 Months Ended			3 Months Ended		6 Months Ended		12 Months Ended
	Jul. 31, 2020 shares	Jan. 31, 2020 USD ($) shares	Jan. 31, 2019 USD ($)	Jun. 30, 2020 USD ($) shares	Jun. 30, 2019 USD ($)	Jun. 30, 2020 USD ($) Investment shares	Jun. 30, 2019 USD ($) shares	Dec. 31, 2019 USD ($)
Related Party Transaction [Line Items]
Total components due to affiliates				$ 613,055,000		$ 613,055,000		$ 690,143,000
Management fee				$ 53,423,000	$ 22,487,000	$ 102,925,000	$ 39,664,000
Stock repurchased | shares				28,592,000		74,313,000
Stock repurchased, value				$ 299,009,000	60,157,000	$ 815,231,000	105,667,000
Portfolio company incentive compensation awards			$ 8,000,000
Amortization period of grant			4 years
Unrecognized compensation cost relating to portfolio company incentive compensation awards				5,000,000		$ 5,000,000
Unrecognized compensation cost recognition period						2 years 6 months
Performance participation allocation return						$ (671,900,000)
Recognized liabilities for Performance Participation expense				0	$ 29,898,000	0	$ 50,061,000
Aggregate redeemable non- controlling interest shares and Class I units continue to own				$ 174,300,000		$ 174,300,000
Class I Shares [Member]
Related Party Transaction [Line Items]
Stock repurchased | shares				15,585,000		34,568,000
Adviser [Member]
Related Party Transaction [Line Items]
Percentage of management fee on NAV per annum						1.25%
Stock repurchased, value						$ 17,800,000		42,100,000
Special Limited Partner [Member]
Related Party Transaction [Line Items]
Percentage of annual hurdle amount						5.00%
Related party allocation percentage of annual total return						12.50%
Special Limited Partner [Member] | Class I Shares [Member]
Related Party Transaction [Line Items]
Stock issued as payment for services | shares		11,700,000
Stock redeemed, shares | shares		7,300,000
Stock redeemed, value		$ 83,600,000
Stock exchanged, shares | shares		800,000
Special Limited Partner [Member] | Class B Shares [Member]
Related Party Transaction [Line Items]
Stock issued as payment for services | shares		700,000
Stock redeemed, shares | shares		7,300,000
All Other Unit Holders [Member]
Related Party Transaction [Line Items]
Related party allocation percentage of annual total return						87.50%
LivCor L.L.C. [Member] | Other Assets [Member]
Related Party Transaction [Line Items]
Receivable from affiliates				$ 3,900,000		$ 3,900,000		3,600,000
LNLS [Member]
Related Party Transaction [Line Items]
Costs paid to LNLS for title services related to investments						$ 2,400,000
Number of Investments with Capitalized or Deferred Financing Costs | Investment						15
Accrued Stockholder Servicing Fee [Member]
Related Party Transaction [Line Items]
Total components due to affiliates				558,132,000		$ 558,132,000		478,539,000
Advanced Organization and Offering Costs [Member]
Related Party Transaction [Line Items]
Total components due to affiliates				5,113,000		5,113,000		6,136,000
Advanced Expenses [Member]
Related Party Transaction [Line Items]
Total components due to affiliates				2,200,000		2,200,000		2,000,000
Accrued Management Fee [Member]
Related Party Transaction [Line Items]
Total components due to affiliates				18,207,000		18,207,000		13,873,000
Accrued Management Fee [Member] | Adviser [Member]
Related Party Transaction [Line Items]
Total components due to affiliates				$ 18,200,000		$ 18,200,000		$ 13,900,000
Management Fee [Member] | Adviser [Member] | Class I Shares [Member]
Related Party Transaction [Line Items]
Stock issued as payment for services | shares						7,822,791	2,870,390
Stock repurchased | shares						4,985,753	4,574,431
Stock repurchased, value						$ 52,300,000	$ 49,900,000
Management Fee [Member] | Subsequent Event [Member] | Adviser [Member] | Class I Shares [Member]
Related Party Transaction [Line Items]
Stock issued as payment for services | shares	1,700,028