Equity - Schedule of Information with Respect to ATM Program (Parenthetical) (Detail) - USD ($) $ / shares in Units, $ in Thousands	6 Months Ended
Jun. 30, 2021	Jun. 30, 2020
Subsidiary Sale Of Stock [Line Items]
Net Proceeds	$ 40,403	$ 109,321
2019 ATM Program [Member]
Subsidiary Sale Of Stock [Line Items]
Number of Shares Sold	3,499,697
Net Proceeds	$ 83,800
Price per share	$ 23.96

Number of new stock issued during the period.

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Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration