Consolidated Statements Of Comprehensive Income / (Loss) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Statement of Comprehensive Income [Abstract]
Net Income	$ 97.5	$ 81.3	$ 64.6	$ 82.8
Foreign Currency Translation
Foreign currency translation gain / (loss) arising during period	15.4	(65.7)	32.6	(67.0)
Adjustment for accumulated foreign currency translation loss reclassified into earnings	0.0	0.0	11.9	0.0
Net foreign currency translation gain / (loss)	15.4	(65.7)	44.5	(67.0)
Cash Flow Hedges
Change in unrealized gain on interest rate derivatives	19.0	9.8	10.4	35.0
Less: Interest rate derivative gains reclassified to earnings	(3.2)	(0.8)	(5.5)	(0.8)
Net unrealized gain on interest rate derivatives	15.8	9.0	4.9	34.2
Total Comprehensive Income	128.7	24.6	114.0	50.0
Less: Comprehensive income attributable to noncontrolling interests	(5.7)	(1.7)	(1.1)	(0.6)
Comprehensive Income attributable to SUI	$ 123.0	$ 22.9	$ 112.9	$ 49.4