Equity and Accumulated Other Comprehensive Loss, Net (7.000% Series E Cumulative Convertible Preferred Stock Narrative) (Details) - Series E Preferred Stock and Unit $ / shares in Units, $ in Millions		12 Months Ended
	Sep. 15, 2011 USD ($) shares	Dec. 31, 2015 quarter $ / shares shares	Dec. 31, 2014 $ / shares shares
Class of Stock [Line Items]
Preferred stock, shares issued (in shares) | shares	11,500,000	11,500,000	11,500,000
Preferred Stock, dividend rate	7.00%	7.00%	7.00%
Gross proceeds from issuance of redeemable preferred stock | $	$ 277.2
Annual rate of dividend per share (in dollars per share)		$ 1.75
Preferred stock, liquidation preference per share/unit		25	$ 25
Preferred stock, dividends in arrears per share		0.515278
Preferred stock, redemption price per share (in dollars per share)		$ 25.00
Number of quarters with no dividends triggering voting rights | quarter		6
Shares issued upon conversion | shares		0.8378