Equity - Dividends and Distributions (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Equity [Abstract]
Dividends paid to common shareholders	$ 18,700	$ 17,600	$ 37,200	$ 34,800
Distributions paid to OP unitholders	13,300	14,300	26,500	28,600
Private perpetual preferred unit distributions	$ 200	$ 200	$ 468	$ 468