Restructuring Expense (Details 2) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended				96 Months Ended
	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2010	Sep. 30, 2010	Jun. 30, 2010	Mar. 31, 2010	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009	Dec. 31, 2003	Dec. 31, 2011
Restructuring activities
Lease restructuring liability at beginning of period				$ 29,595				$ 34,017	$ 29,595	$ 34,017	$ 34,064		$ 69,526
Cash payments									(14,904)	(14,759)	(14,924)	(17,816)	(148,844)
Cash received from subleases									9,548	8,836	8,637		55,014
Credit for portion of facility the entity decided to occupy in 2005													(10,018)
Restructuring expense	992	(419)	741	760	(2,257)	866	2,112	780	2,074	1,501	6,240	91,824	60,635
Lease restructuring liability at end of period	$ 26,313				$ 29,595				$ 26,313	$ 29,595	$ 34,017	$ 69,526	$ 26,313