Accrued Expenses (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2011	Dec. 31, 2010
Accrued Liabilities [Abstract]
Accrued Compensation and benefits	$ 31,053	$ 25,934
Dividends payable	10,719	10,960
Accrued interest	4,908	5,280
Termination benefits (see note 26)	4,522	3,269
Other liabilities and contingencies	2,649	2,375
Total	$ 53,851	$ 47,818