Debt (Components Of Interest Expense) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011
Debt [Line Items]
Amortization of amendment and arrangement fees	$ 429	$ 445
Commitment fees	312	306
Sub-total	741	751
Interest Expense	10,108	10,388
Other interest expense	287	377
Total interest expense	10,108	10,388
York Property Mortgage [Member]
Debt [Line Items]
Interest Expense	4,182	4,188
Senior Notes [Member]
Debt [Line Items]
Interest Expense	1,587	1,584
Convertible Notes [Member]
Debt [Line Items]
Interest Expense	$ 3,311	$ 3,488