Financial Highlights - Schedule of Financial Highlights (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2022		Mar. 31, 2021	Dec. 31, 2021		Dec. 31, 2020
OPERATING PERFORMANCE PER SHARE
Net investment income (usd per share)	$ 0.25		$ 0.23
Net assets, end of period	$ 541,710	[1],[2]	$ 346,477	$ 500,309	[3],[4]	$ 308,962
Distributions declared	$ 4,928		$ 3,290
Class FA
OPERATING PERFORMANCE PER SHARE
Net Asset Value, Beginning of Period (usd per shares)	$ 32.62		$ 29.97
Net investment income, before expense support (usd per shares)	0.49		0.10
Expense support (usd per shares)	(0.20)		0.18
Net investment income (usd per share)	0.29		0.28
Net realized and unrealized gains (usd per shares)	0.68		1.28
Net increase resulting from investment operations (usd per shares)	0.97		1.56
Distributions from net investment income (usd per share)	(0.31)		(0.31)
Net Decrease Resulting From Distributions to Shareholders, Per Share (usd per shares)	(0.31)		(0.31)
Net Asset Value, End of Period (usd per shares)	$ 33.28		$ 31.22
Net assets, end of period	$ 147,112		$ 142,896	148,717
Average net assets	$ 149,800		$ 139,658
Shares outstanding end of period (in shares)	4,421		4,577
Distributions declared	$ 1,424		$ 1,431
Total investment return based on net asset value before total return incentive fee	3.34%		5.20%
Investment Company, Total Return after Incentive Fees	2.95%		5.20%
Ratios to average net assets:
Total operating expenses before total return incentive fee and Expense Support	0.33%		0.34%
Total operating expenses before Expense Support	0.66%		0.85%
Total operating expenses after Expense Support	1.24%		0.25%
Net investment income before total return incentive fee	1.22%		0.92%
Net investment income	0.90%		0.92%
Class A
OPERATING PERFORMANCE PER SHARE
Net Asset Value, Beginning of Period (usd per shares)	$ 30.78		$ 28.76
Net investment income, before expense support (usd per shares)	0.29		(0.13)
Expense support (usd per shares)	(0.13)		0.28
Net investment income (usd per share)	0.16		0.15
Net realized and unrealized gains (usd per shares)	0.68		1.28
Net increase resulting from investment operations (usd per shares)	0.84		1.43
Distributions from net investment income (usd per share)	(0.31)		(0.31)
Net Decrease Resulting From Distributions to Shareholders, Per Share (usd per shares)	(0.31)		(0.31)
Net Asset Value, End of Period (usd per shares)	$ 31.31		$ 29.88
Net assets, end of period	$ 50,399		$ 33,685	$ 44,958
Average net assets	$ 46,920		$ 31,449
Shares outstanding end of period (in shares)	1,610		1,127	1,461
Distributions declared	$ 473		$ 335
Total investment return based on net asset value before total return incentive fee	3.40%		5.05%
Investment Company, Total Return after Incentive Fees	2.75%		5.01%
Ratios to average net assets:
Total operating expenses before total return incentive fee and Expense Support	0.80%		0.72%
Total operating expenses before Expense Support	1.49%		1.72%
Total operating expenses after Expense Support	1.91%		0.75%
Net investment income before total return incentive fee	1.20%		0.54%
Net investment income	0.52%		0.51%
Total investment return based on net asset value after total return incentive fee			97.00%
Class T
OPERATING PERFORMANCE PER SHARE
Net Asset Value, Beginning of Period (usd per shares)	$ 30.66		$ 28.67
Net investment income, before expense support (usd per shares)	0.21		(0.21)
Expense support (usd per shares)	0		0.24
Net investment income (usd per share)	0.21		0.03
Net realized and unrealized gains (usd per shares)	0.66		1.29
Net increase resulting from investment operations (usd per shares)	0.87		1.32
Distributions from net investment income (usd per share)	(0.25)		(0.25)
Net Decrease Resulting From Distributions to Shareholders, Per Share (usd per shares)	(0.25)		(0.25)
Net Asset Value, End of Period (usd per shares)	$ 31.28		$ 29.74
Net assets, end of period	$ 53,038		$ 22,485	$ 49,328
Average net assets	$ 50,365		$ 19,893
Shares outstanding end of period (in shares)	1,695		756	1,609
Distributions declared	$ 408		$ 170
Total investment return based on net asset value before total return incentive fee	3.55%		4.73%
Investment Company, Total Return after Incentive Fees	2.85%		4.63%
Ratios to average net assets:
Total operating expenses before total return incentive fee and Expense Support	0.98%		1.08%
Total operating expenses before Expense Support	1.71%		2.04%
Total operating expenses after Expense Support	1.71%		1.20%
Net investment income before total return incentive fee	1.41%		0.22%
Net investment income	0.68%		0.10%
Total investment return based on net asset value after total return incentive fee			88.00%
Class D
OPERATING PERFORMANCE PER SHARE
Net Asset Value, Beginning of Period (usd per shares)	$ 30.35		$ 28.24
Net investment income, before expense support (usd per shares)	0.24		(0.17)
Expense support (usd per shares)	0		0.25
Net investment income (usd per share)	0.24		0.08
Net realized and unrealized gains (usd per shares)	0.66		1.29
Net increase resulting from investment operations (usd per shares)	0.90		1.37
Distributions from net investment income (usd per share)	(0.28)		(0.28)
Net Decrease Resulting From Distributions to Shareholders, Per Share (usd per shares)	(0.28)		(0.28)
Net Asset Value, End of Period (usd per shares)	$ 30.97		$ 29.33
Net assets, end of period	$ 36,225		$ 15,062	$ 30,607
Average net assets	$ 31,922		$ 13,486
Shares outstanding end of period (in shares)	1,170		514	1,009
Distributions declared	$ 294		$ 132
Total investment return based on net asset value before total return incentive fee	3.68%		4.99%
Investment Company, Total Return after Incentive Fees	2.98%		4.88%
Ratios to average net assets:
Total operating expenses before total return incentive fee and Expense Support	1.00%		0.89%
Total operating expenses before Expense Support	1.77%		1.90%
Total operating expenses after Expense Support	1.77%		1.03%
Net investment income before total return incentive fee	1.55%		0.42%
Net investment income	0.78%		0.28%
Total investment return based on net asset value after total return incentive fee			86.00%
Class I
OPERATING PERFORMANCE PER SHARE
Net Asset Value, Beginning of Period (usd per shares)	$ 31.18		$ 29.06
Net investment income, before expense support (usd per shares)	0.28		(0.20)
Expense support (usd per shares)	(0.10)		0.37
Net investment income (usd per share)	0.18		0.17
Net realized and unrealized gains (usd per shares)	0.68		1.29
Net increase resulting from investment operations (usd per shares)	0.86		1.46
Distributions from net investment income (usd per share)	(0.31)		(0.31)
Net Decrease Resulting From Distributions to Shareholders, Per Share (usd per shares)	(0.31)		(0.31)
Net Asset Value, End of Period (usd per shares)	$ 31.73		$ 30.21
Net assets, end of period	$ 195,476		$ 76,841	$ 168,704
Average net assets	$ 178,731		$ 63,678
Shares outstanding end of period (in shares)	6,160		2,544	5,410
Distributions declared	$ 1,777		$ 668
Total investment return based on net asset value before total return incentive fee	3.43%		5.06%
Investment Company, Total Return after Incentive Fees	2.78%		5.06%
Ratios to average net assets:
Total operating expenses before total return incentive fee and Expense Support	0.83%		0.98%
Total operating expenses before Expense Support	1.53%		2.01%
Total operating expenses after Expense Support	1.85%		0.76%
Net investment income before total return incentive fee	1.28%		0.57%
Net investment income	0.58%		0.57%
Class S
OPERATING PERFORMANCE PER SHARE
Net Asset Value, Beginning of Period (usd per shares)	$ 32.84		$ 30.08
Net investment income, before expense support (usd per shares)	0.47		0.06
Expense support (usd per shares)	0		0.25
Net investment income (usd per share)	0.47		0.31
Net realized and unrealized gains (usd per shares)	0.67		1.27
Net increase resulting from investment operations (usd per shares)	1.14		1.58
Distributions from net investment income (usd per share)	(0.31)		(0.31)
Net Decrease Resulting From Distributions to Shareholders, Per Share (usd per shares)	(0.31)		(0.31)
Net Asset Value, End of Period (usd per shares)	$ 33.67		$ 31.35
Net assets, end of period	$ 59,460		$ 55,510
Average net assets	$ 58,456		$ 54,199
Shares outstanding end of period (in shares)	1,766		1,770
Distributions declared	$ 552		$ 553
Total investment return based on net asset value before total return incentive fee	3.88%		5.29%
Investment Company, Total Return after Incentive Fees	3.49%		5.29%
Ratios to average net assets:
Total operating expenses before total return incentive fee and Expense Support	0.37%		0.44%
Total operating expenses before Expense Support	0.75%		0.96%
Total operating expenses after Expense Support	0.75%		0.16%
Net investment income before total return incentive fee	1.80%		1.02%
Net investment income	1.42%		1.02%
Class FA, Class I, and Class S
Ratios to average net assets:
Total investment return based on net asset value after total return incentive fee			100.00%

[1] Percentages represent fair value as a percentage of net assets for each investment category.

[2] Security may be an obligation of one or more entities affiliated with the named company.

[3] Percentages represent fair value as a percentage of net assets for each investment category.

[4] Security may be an obligation of one or more entities affiliated with the named company.