Equity Stock Redeemed and Retired (Details) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013		Sep. 30, 2012
Class of Stock [Line Items]
Discount (Deemed negative dividend)	$ 0	$ 0	$ 0		$ 229
8.05% Series B Cumulative Redeemable Preferred Stock [Member]
Class of Stock [Line Items]
Shares redeemed and retired			0		2,740,874
Redemption and Repurchase Costs			0	[1]	69,459	[1]
Deemed dividend	0	0	0	[2]	2,346	[2]
6.50% Series C Cumulative Convertible Preferred Stock [Member]
Class of Stock [Line Items]
Redemption and Repurchase Costs			0		1,462
Shares repurchased and retired			0		34,800
Discount (Deemed negative dividend)			0	[2]	(229)	[2]
7.55% Series D Cumulative Redeemable Preferred Stock [Member]
Class of Stock [Line Items]
Shares redeemed and retired			6,200,000		0
Redemption and Repurchase Costs			155,621	[1]	0	[1]
Deemed dividend	$ 0	$ 0	$ 5,230	[2]	$ 0	[2]

[1] Includes accrued and unpaid dividends.

[2] Represents the difference between the redemption/repurchase cost and historical GAAP cost.