Disclosures About Offsetting Assets and Liabilities (Financial Assets and Derivative Assets that are Subject to Offset) (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Offsetting [Abstract]
Gross amounts of recognized assets, Securities borrowing	$ 314,154	$ 313,131
Net amounts presented in the Statement of Financial Condition, Securities borrowing	314,154	313,131
Gross amounts not offset in the Statement of Financial Position, Financial instruments, Securities borrowing	(39,225)	(46,183)
Gross amounts not offset in the Statement of Financial Position, Collateral received, Securities borrowing	(260,229)	(244,578)
Securities borrowed, Net amount	14,700	22,370
Gross amounts of recognized assets, Reverse repurchase agreements	598,535	217,930
Net amounts presented in the Statement of Financial Condition, Securities purchased under agreements to resell	598,535	217,930
Gross amounts not offset in the Statement of Financial Position, Financial instruments, Securities purchased under agreements to resell	(10,655)	(17,992)
Gross amounts not offset in the Statement of Financial Position, Collateral received, Securities purchased under agreements to resell	(584,240)	(199,110)
Securities purchased under agreements to resell, Net amount	3,640	828
Gross amounts of recognized assets	912,689	531,061
Net amounts presented in the Statements of Financial Condition	912,689	531,061
Gross amounts not offset in the Statement of Financial Position	(49,880)	(64,175)
Gross amounts not offset in the Statement of Financial Position, Collateral received	(844,469)	(443,688)
Net amount	$ 18,340	$ 23,198