Real Estate Facilities (Schedule Of Real Estate Activities) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Real Estate Facilities [Abstract]
Beginning balance (Operating facilities, at cost)	$ 15,296,844	$ 14,665,989	$ 13,963,229
Costs incurred for capital expenditures to maintain real estate facilities	192,539	139,397	124,780
Acquisitions	421,097	169,436	274,115
Dispositions	(426)	(25,633)	(1,092)
Hurricane damage			(8,226)
Developed or expanded facilities opened for operation	379,092	348,270	311,559
Impact of foreign exchange rate changes		(615)	1,624
Ending balance (Operating facilities, at cost)	16,289,146	15,296,844	14,665,989
Beginning balance (Accumulated depreciation)	(6,140,072)	(5,700,331)	(5,270,963)
Depreciation expense	(483,408)	(457,029)	(433,466)
Dispositions	5	16,876	123
Hurricane damage			4,940
Impact of foreign exchange rate changes		412	(965)
Ending balance (Accumulated depreciation)	(6,623,475)	(6,140,072)	(5,700,331)
Beginning balance (Construction in process)	285,339	264,441	230,310
Costs incurred for development and expansion of real estate facilities	235,687	362,397	349,712
Developed or expanded facilities opened for operations	(379,092)	(348,270)	(311,559)
Dispositions		(2,698)	(4,022)
Transfer from other assets		9,469
Ending balance (Construction in process)	141,934	285,339	264,441
Total real estate facilities	$ 9,807,605	$ 9,442,111	$ 9,230,099