Receivables from Brokerage Clients	12 Months Ended
Dec. 31, 2011
Receivables from Brokerage Clients	4. Receivables from Brokerage Clients Receivables from brokerage clients are recorded net of an allowance for doubtful accounts. The allowance for doubtful accounts was not material at December 31, 2011 or 2010. Receivables from brokerage clients consist primarily of margin loans to brokerage clients of $10.2 billion and $10.3 billion at December 31, 2011 and 2010, respectively. Securities owned by brokerage clients are held as collateral for margin loans. Such collateral is not reflected in the consolidated financial statements. The average yield earned on margin loans was 4.39% and 4.87% in 2011 and 2010, respectively.

Receivables from Brokerage Clients

12 Months Ended

Dec. 31, 2011

4. Receivables from Brokerage Clients

Receivables from brokerage clients are recorded net of an allowance for doubtful accounts. The allowance for doubtful accounts was not material at December 31, 2011 or 2010. Receivables from brokerage clients consist primarily of margin loans to brokerage clients of $10.2 billion and $10.3 billion at December 31, 2011 and 2010, respectively. Securities owned by brokerage clients are held as collateral for margin loans. Such collateral is not reflected in the consolidated financial statements. The average yield earned on margin loans was 4.39% and 4.87% in 2011 and 2010, respectively.