Debt Schedule of Maturities of Long-term Debt Parenthetical (Details) (USD $)	Dec. 31, 2013	Dec. 31, 2012	Aug. 31, 2009
Senior Exchangeable Notes due 2015 at a fixed interest rate of 4.50% [Member]
Debt Instrument [Line Items]
Unamortized discount	$ 3,224,000	$ 6,679,000
Amount due upon maturity	130,973,000	172,500,000	172,500,000.0
Senior Exchangeable Notes due 2015 at a fixed interest rate of 4.50%, post 2013 paydowns [Member]
Debt Instrument [Line Items]
Amount due upon maturity	131,000,000
Mortgage notes due 2017 at fixed interest rates of 4.35% [Member]
Debt Instrument [Line Items]
Amount due upon maturity	63,000,000
Unamortized premium	$ 2,200,000	$ 3,200,000