Disclosures About Offsetting Assets And Liabilities (Financial Liabilities And Derivative Liabilities That Are Subject To Offset) (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2013		Dec. 31, 2012
Disclosures About Offsetting Assets And Liabilities [Abstract]
Gross amounts of recognized liabilities, Securities lending	$ 40,101	[1]	$ 19,218	[1]
Gross amounts offset in the Statement of Financial Condition, Securities lending		[1]		[1]
Net amounts presented in the Statement of Financial Condition, Securities lending	40,101	[1]	19,218	[1]
Gross amounts not offset in the Statement of Financial Position, Financial instruments, Securities loaned		[1]		[1]
Gross amounts not offset in the Statement of Financial Position, Collateral pledged, Securities lending	(40,101)	[1]	(19,218)	[1]
Securities lending, Net amount		[1]		[1]
Gross amounts of recognized liabilities, Securities purchased under agreements to resell	263,809		140,346
Gross amounts offset in the Statement of Financial Condition, Securities purchased under agreements to resell
Net amounts presented in the Statement of Financial Condition, Securities purchased under agreeemnts to resell	263,809		140,346
Gross amounts not offset in the Statement of Financial Position, Financial instruments, Securities purchased under agreements to resell
Gross amounts not offset in the Statement of Financial Position, Collateral pledged, Securities purchased under agreements to resell	(263,809)		(140,346)
Securities purchased under agreements to repurchase, Net amount
Gross amount of recognized liabilities, Cash flow interest rate contracts	9,349		19,934
Gross amounts offset in the Statement of Financial Condition, Cash flow interest rate contracts
Net amounts presented in the Statement of Financial Condition, Cash flow interest rate contracts	9,349		19,934
Gross amounts not offset in the Statement of Financial Position, Financial instruments, Cash flow interest rate contracts
Gross amounts not offset in the Statement of Financial Position, Collateral pledged, Cash flow interest rate contracts	(9,349)		(19,934)
Cash flow interest rate contracts, Net amount
Gross amounts of recognized liabilities	313,259		179,498
Gross amounts offset in the Statement of Financial Condition
Net amounts presented in the Statement of Financial Condition	313,259		179,498
Gross amounts not offset in the Statement of Financial Position, Financial instruments
Gross amounts not offset in the Statement of Financial position, Collateral pledged	(313,259)		(179,498)
Net amount

[1] Securities lending transactions are included in payables to from brokers, dealers, and clearing organizations on the consolidated statements of financial condition. See Note 5 in the notes to our consolidated financial statements for additional information on payables to brokers, dealers, and clearing organizations.(4)