Capital Transactions - Summary of Shares Issued and Proceeds Received in Connection with Offerings (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021	Dec. 31, 2021
Investment Company, Capital Share Transactions [Line Items]
Proceeds to Company	$ 1,955	$ 1,152	$ 5,271	$ 2,797
Shares (in shares)			4,341	3,830
Net proceeds to company			$ 136,747	$ 116,476
Average Net Proceeds per Share (usd per share)	$ 31.49	$ 30.41	$ 31.49	$ 30.41
Receivable for shares sold	$ 17,042	$ 16,700	$ 17,042	$ 16,700	$ 0
Proceeds from Public Offerings
Investment Company, Capital Share Transactions [Line Items]
Shares issued (in shares)			4,173	3,737
Gross Proceeds			$ 133,500	$ 115,342
Sales Load			(2,024)	(1,663)
Net Proceeds to Company			$ 131,476	$ 113,679
Distribution Reinvestment Plan
Investment Company, Capital Share Transactions [Line Items]
Issuance of common shares through distribution reinvestment plan (in shares)			168	93
Proceeds to Company			$ 5,271	$ 2,797
Class A
Investment Company, Capital Share Transactions [Line Items]
Shares (in shares)			541	342
Net proceeds to company			$ 16,959	$ 10,317
Average Net Proceeds per Share (usd per share)	$ 31.31	$ 30.17	$ 31.31	$ 30.17
Class A | Proceeds from Public Offerings
Investment Company, Capital Share Transactions [Line Items]
Shares issued (in shares)			503	310
Gross Proceeds			$ 16,978	$ 10,087
Sales Load			(1,232)	(735)
Net Proceeds to Company			$ 15,746	$ 9,352
Class A | Distribution Reinvestment Plan
Investment Company, Capital Share Transactions [Line Items]
Issuance of common shares through distribution reinvestment plan (in shares)			38	32
Proceeds to Company			$ 1,213	$ 965
Class T
Investment Company, Capital Share Transactions [Line Items]
Shares (in shares)			557	656
Net proceeds to company			$ 17,423	$ 19,881
Average Net Proceeds per Share (usd per share)	31.28	30.30	$ 31.28	$ 30.30
Class T | Proceeds from Public Offerings
Investment Company, Capital Share Transactions [Line Items]
Shares issued (in shares)			531	644
Gross Proceeds			$ 17,394	$ 20,442
Sales Load			(792)	(928)
Net Proceeds to Company			$ 16,602	$ 19,514
Class T | Distribution Reinvestment Plan
Investment Company, Capital Share Transactions [Line Items]
Issuance of common shares through distribution reinvestment plan (in shares)			26	12
Proceeds to Company			$ 821	$ 367
Class D
Investment Company, Capital Share Transactions [Line Items]
Shares (in shares)			664	465
Net proceeds to company			$ 20,586	$ 13,954
Average Net Proceeds per Share (usd per share)	30.96	30.02	$ 30.96	$ 30.02
Class D | Proceeds from Public Offerings
Investment Company, Capital Share Transactions [Line Items]
Shares issued (in shares)			646	456
Gross Proceeds			$ 20,010	$ 13,691
Sales Load			0	0
Net Proceeds to Company			$ 20,010	$ 13,691
Class D | Distribution Reinvestment Plan
Investment Company, Capital Share Transactions [Line Items]
Issuance of common shares through distribution reinvestment plan (in shares)			18	9
Proceeds to Company			$ 576	$ 263
Class I
Investment Company, Capital Share Transactions [Line Items]
Shares (in shares)			2,579	2,367
Net proceeds to company			$ 81,779	$ 72,324
Average Net Proceeds per Share (usd per share)	$ 31.71	$ 30.55	$ 31.71	$ 30.55
Class I | Proceeds from Public Offerings
Investment Company, Capital Share Transactions [Line Items]
Shares issued (in shares)			2,493	2,327
Gross Proceeds			$ 79,118	$ 71,122
Sales Load			0	0
Net Proceeds to Company			$ 79,118	$ 71,122
Class I | Distribution Reinvestment Plan
Investment Company, Capital Share Transactions [Line Items]
Issuance of common shares through distribution reinvestment plan (in shares)			86	40
Proceeds to Company			$ 2,661	$ 1,202