Restructuring Costs (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Pre-tax restructuring costs:
Employee severance and benefits		$ 525	$ 5,186
Termination of certain office leases	1,200	647	1,867
Other	353	686	753
Total restructuring costs	1,553	1,858	7,806
Included in Accounts Payable, Accrued Expenses and Other Liabilities, Net related to severance Obligations, remaining lease payments and other costs incurred but not yet paid	1,959	1,574	2,884
Summarization of Restructuring Costs Details (Textual) [Abstract]
Non cash costs representing accelerated recognition of restricted stock expense	$ 0	$ 156	$ 2,931