Noncontrolling Interests - Narrative (Details)	1 Months Ended	12 Months Ended
	May 31, 2021 joint_venture	Dec. 31, 2020 joint_venture	Sep. 30, 2021 joint_venture noncontrolling_interest
Noncontrolling interests
Number of noncontrolling interests consolidated | noncontrolling_interest			4
Number of development joint ventures			2
Number of development joint ventures acquired	1	1
Consolidated joint venture
Noncontrolling interests
Ownership interest (as a percent)			85.20%