Equity (Details 1)	3 Months Ended
	Mar. 31, 2017 $ / shares
6.50% Series C [Member]
Dividends on preferred shares/units
Dividend per Share (usd per share)	$ 0.41
Record Date	Mar. 31, 2017
Payable Date	Apr. 17, 2017
6.375% Series D [Member]
Dividends on preferred shares/units
Dividend per Share (usd per share)	$ 0.40
Record Date	Mar. 31, 2017
Payable Date	Apr. 17, 2017