Equity Additional Information (Detail) - USD ($) $ / shares in Units, $ in Thousands	1 Months Ended	3 Months Ended			9 Months Ended
	Apr. 30, 2021	Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2021	Sep. 30, 2021	Sep. 30, 2020
Class Of Stock [Line Items]
Common shares, issued				17,250,000
Proceeds from issuance of common shares, net of offering expenses				$ 225,200	$ 225,166	$ 0
Write-off of preferred share original issuance costs					$ 5,100	$ 0
Class K Cumulative Redeemable Preferred Shares [Member]
Class Of Stock [Line Items]
Preferred stock, liquidation preference, value	$ 150,000
Cumulative redeemable preferred shares, liquidation value	$ 500
Per share price of depositary share	25.00
Redeemable preferred stock dividend per share prorated to redemption date	7.2049
Redeemable preferred stock dividend per depositary share prorated to redemption date	$ 0.3602
Write-off of preferred share original issuance costs	$ 5,100
Continuous Equity Program [Member]
Class Of Stock [Line Items]
Sale of common shares, value			$ 250,000
Forward Sale Agreement [Member]
Class Of Stock [Line Items]
Sale of common shares		720,076	980,396		1,700,472
Weighted-average price		$ 15.89	$ 15.09		$ 15.43
Sale of common shares, value		$ 11,400	$ 14,800		$ 26,200
Forward contract, equity, settlement date		Sep. 09, 2022	Jul. 01, 2022