SHAREHOLDERS' EQUITY (DETAILS 4) (USD $) In Thousands, except Share data, unless otherwise specified	12 Months Ended			1 Months Ended				6 Months Ended		12 Months Ended		1 Months Ended		12 Months Ended			0 Months Ended	1 Months Ended	12 Months Ended		0 Months Ended	1 Months Ended	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Jun. 30, 2013 Series A 7.25% Preferred Shares [Member]	Dec. 17, 2012 Series A 7.25% Preferred Shares [Member]	Mar. 31, 2012 Series A 7.25% Preferred Shares [Member]	Oct. 31, 2005 Series A 7.25% Preferred Shares [Member]	Jun. 30, 2013 Series A 7.25% Preferred Shares [Member]	Jul. 15, 2013 Series A 7.25% Preferred Shares [Member]	Dec. 31, 2012 Series A 7.25% Preferred Shares [Member]	Dec. 31, 2011 Series A 7.25% Preferred Shares [Member]	Apr. 30, 2013 Series B 7.50% Preferred Shares [Member]	Nov. 30, 2005 Series B 7.50% Preferred Shares [Member]	Dec. 31, 2013 Series B 7.50% Preferred Shares [Member]	Dec. 31, 2012 Series B 7.50% Preferred Shares [Member]	Dec. 31, 2011 Series B 7.50% Preferred Shares [Member]	Jan. 15, 2013 Series C 6.875% Preferred Shares [Member]	Mar. 31, 2012 Series C 6.875% Preferred Shares [Member]	Dec. 31, 2013 Series C 6.875% Preferred Shares [Member]	Dec. 31, 2012 Series C 6.875% Preferred Shares [Member]	Mar. 03, 2014 Series D 5.50% Preferred Shares [Member]	May 31, 2013 Series D 5.50% Preferred Shares [Member]	Dec. 31, 2013 Series D 5.50% Preferred Shares [Member]
Class of Stock [Line Items]
Preferred shares, aggregate liquidation value issued							$ 250,000						$ 250,000					$ 400,000				$ 225,000
Preferred shares, dividend rate								7.25%						7.50%					6.875%				5.50%
Preferred shares, aggregate liquidation preference repurchased				100,000		150,000
Preferred shares, par value per share				$ 0.0125				$ 0.0125						$ 0.0125					$ 0.0125				$ 0.0125
Preferred shares, liquidation preference per share				$ 25.00				$ 25.00						$ 100.00					$ 25.00				$ 25.00
Preferred shares, redemption price per share														$ 100.00					$ 25.00				$ 25.00
Preferred shares, floating dividend rate base														3.4525%
Preferred shares, dividend declared per share					$ 0.4531			$ 0.9063		$ 1.8125	$ 1.8125			$ 7.50	$ 7.50	$ 7.50			$ 1.7188	$ 1.4132			$ 0.6875
Preferred shares, dividends paid per share									$ 1.3594	$ 1.8125	$ 1.8125			$ 7.50	$ 7.50	$ 7.50	$ 0.4297		$ 1.7188	$ 0.9835	$ 0.3438		$ 0.3438
Preferred shares, number of shares repurchased				4,000,000		6,000,000						2,471,570
Loss on repurchase of preferred shares	3,081	14,009	0	3,000		5,000						9,000
Preferred shares, number of shares outstanding														28,430
Preferred shares, aggregate liquidation value outstanding	627,843	502,843												3,000					400,000
Preferred shares, purchase price per share												$ 102.81
Aggregate cash payment to acquire preferred shares	$ 100,000	$ 404,073	$ 0									$ 254,000