(Common Units) (Narrative) (Details) $ / shares in Units, $ in Millions		9 Months Ended
	Feb. 06, 2020 USD ($) shares	Sep. 30, 2020 USD ($) yr $ / shares shares
MYLTIP 2017 [Member]
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
Final awards percentage of target	83.80%
Value of MYLTIP Awards | $	$ 17.6
MYLTIP Units forfeited	270,942
OP Units [Member]
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Effects of Changes, Net [Line Items]
OP Units for redemption (in shares)		773,858
Redemption of OP units issued on conversion of LTIP, OPP and MYLTIP units (in shares)		82,608
MYLTIP Units distribution as percentage of OP Unit distribution prior to measurement date		10.00%
Restriction on redemption of OP Unit to Common Stock (in years) | yr		1
Redemption of OP Unit equivalent to Common Stock (in shares)		1
Common units of operating partnership if converted value | $		$ 1,400.0
Closing price of common stock (in dollars per share) | $ / shares		$ 80.30