Summary of Significant Accounting Policies Summary of Significant Accounting Policies 4 (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012 trust_accounts	Dec. 31, 2011 trust_accounts
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Number of Trust Accounts managed or administered	1,486	1,407
Value of Trust Accounts	$ 633,800	$ 546,658