Stockholder's Equity (Details Textuals) $ / shares in Units, $ in Thousands	3 Months Ended			12 Months Ended
	Mar. 31, 2012 $ / shares shares	Mar. 31, 2011 $ / shares shares	Dec. 31, 2010 shares	Dec. 31, 2015 USD ($)	Dec. 31, 2014 USD ($)	Dec. 31, 2013 USD ($) shares
Stockholders' Equity (Details) [Abstract]
Acquisitions of non controlling interests | $				$ 5,663	$ 1,175	$ 23,247
Equity issued in acquisition of noncontrolling interest						1,108,917
Total purchase price | $						$ 91,000
Percentage of partnership owned						20.00%
Transaction costs existing partnership | $						$ 2,732
Series H Preferred Stock [Member]
Preferred Stock [Line Items]
Preferred stock, shares issued			349,854
Preferred stock balance issued average rate			0.06
Series I Preferred Stock [Member]
Preferred Stock [Line Items]
Preferred stock, shares issued		14,375,000
Preferred stock balance issued average rate		0.065
Equivalent Number Of Common Stock On Conversion Of Preferred Shares		0.846
Initial conversion Price | $ / shares		$ 59.1
Liquidation value per preferred share | $ / shares		$ 50
Series J Preferred Stock [Member]
Preferred Stock [Line Items]
Preferred stock, shares issued	11,500,000
Preferred stock balance issued average rate	0.065
Redemption date, preferred stock	Mar. 07, 2017
Initial conversion Price | $ / shares	$ 25