Fair Value - Partnership's Financial Assets at Fair Value (Detail) (USD $) | Sep. 26, 2014 | Dec. 31, 2013 |
In Millions, unless otherwise specified |
Investments segregated under federal regulations: | ' | ' |
Total investments segregated under federal regulations | $1,282 | $1,379 |
Inventory securities: | ' | ' |
Total inventory securities | 86 | 102 |
Investment securities: | ' | ' |
Total investment securities | 153 | 141 |
Other [Member] | ' | ' |
Inventory securities: | ' | ' |
Total inventory securities | 2 | 1 |
Investment securities: | ' | ' |
Total investment securities | 1 | 1 |
Mutual funds [Member] | ' | ' |
Investment securities: | ' | ' |
Total investment securities | 129 | 116 |
Government and agency obligations [Member] | ' | ' |
Investment securities: | ' | ' |
Total investment securities | 19 | 19 |
Unit investment trusts [Member] | ' | ' |
Inventory securities: | ' | ' |
Total inventory securities | ' | 2 |
U.S. treasuries [Member] | ' | ' |
Investments segregated under federal regulations: | ' | ' |
Total investments segregated under federal regulations | 1,057 | 1,154 |
State and municipal obligations [Member] | ' | ' |
Inventory securities: | ' | ' |
Total inventory securities | 43 | 67 |
Equities [Member] | ' | ' |
Inventory securities: | ' | ' |
Total inventory securities | 33 | 27 |
Investment securities: | ' | ' |
Total investment securities | 4 | 5 |
Corporate bonds and notes [Member] | ' | ' |
Inventory securities: | ' | ' |
Total inventory securities | 3 | 3 |
Certificates of deposit [Member] | ' | ' |
Investments segregated under federal regulations: | ' | ' |
Total investments segregated under federal regulations | 225 | 225 |
Inventory securities: | ' | ' |
Total inventory securities | 5 | 2 |
Level I [Member] | ' | ' |
Investments segregated under federal regulations: | ' | ' |
Total investments segregated under federal regulations | 1,057 | 1,154 |
Inventory securities: | ' | ' |
Total inventory securities | 34 | 29 |
Investment securities: | ' | ' |
Total investment securities | 152 | 140 |
Level I [Member] | Other [Member] | ' | ' |
Inventory securities: | ' | ' |
Total inventory securities | 1 | 0 |
Investment securities: | ' | ' |
Total investment securities | 0 | 0 |
Level I [Member] | Mutual funds [Member] | ' | ' |
Investment securities: | ' | ' |
Total investment securities | 129 | 116 |
Level I [Member] | Government and agency obligations [Member] | ' | ' |
Investment securities: | ' | ' |
Total investment securities | 19 | 19 |
Level I [Member] | Unit investment trusts [Member] | ' | ' |
Inventory securities: | ' | ' |
Total inventory securities | ' | 2 |
Level I [Member] | U.S. treasuries [Member] | ' | ' |
Investments segregated under federal regulations: | ' | ' |
Total investments segregated under federal regulations | 1,057 | 1,154 |
Level I [Member] | State and municipal obligations [Member] | ' | ' |
Inventory securities: | ' | ' |
Total inventory securities | 0 | 0 |
Level I [Member] | Equities [Member] | ' | ' |
Inventory securities: | ' | ' |
Total inventory securities | 33 | 27 |
Investment securities: | ' | ' |
Total investment securities | 4 | 5 |
Level I [Member] | Corporate bonds and notes [Member] | ' | ' |
Inventory securities: | ' | ' |
Total inventory securities | 0 | 0 |
Level I [Member] | Certificates of deposit [Member] | ' | ' |
Investments segregated under federal regulations: | ' | ' |
Total investments segregated under federal regulations | 0 | 0 |
Inventory securities: | ' | ' |
Total inventory securities | 0 | 0 |
Level II [Member] | ' | ' |
Investments segregated under federal regulations: | ' | ' |
Total investments segregated under federal regulations | 225 | 225 |
Inventory securities: | ' | ' |
Total inventory securities | 52 | 73 |
Investment securities: | ' | ' |
Total investment securities | 1 | 1 |
Level II [Member] | Other [Member] | ' | ' |
Inventory securities: | ' | ' |
Total inventory securities | 1 | 1 |
Investment securities: | ' | ' |
Total investment securities | 1 | 1 |
Level II [Member] | Mutual funds [Member] | ' | ' |
Investment securities: | ' | ' |
Total investment securities | 0 | 0 |
Level II [Member] | Government and agency obligations [Member] | ' | ' |
Investment securities: | ' | ' |
Total investment securities | 0 | 0 |
Level II [Member] | Unit investment trusts [Member] | ' | ' |
Inventory securities: | ' | ' |
Total inventory securities | ' | 0 |
Level II [Member] | U.S. treasuries [Member] | ' | ' |
Investments segregated under federal regulations: | ' | ' |
Total investments segregated under federal regulations | 0 | 0 |
Level II [Member] | State and municipal obligations [Member] | ' | ' |
Inventory securities: | ' | ' |
Total inventory securities | 43 | 67 |
Level II [Member] | Equities [Member] | ' | ' |
Inventory securities: | ' | ' |
Total inventory securities | 0 | 0 |
Investment securities: | ' | ' |
Total investment securities | 0 | 0 |
Level II [Member] | Corporate bonds and notes [Member] | ' | ' |
Inventory securities: | ' | ' |
Total inventory securities | 3 | 3 |
Level II [Member] | Certificates of deposit [Member] | ' | ' |
Investments segregated under federal regulations: | ' | ' |
Total investments segregated under federal regulations | 225 | 225 |
Inventory securities: | ' | ' |
Total inventory securities | 5 | 2 |
Level III [Member] | ' | ' |
Investments segregated under federal regulations: | ' | ' |
Total investments segregated under federal regulations | 0 | 0 |
Inventory securities: | ' | ' |
Total inventory securities | 0 | 0 |
Investment securities: | ' | ' |
Total investment securities | 0 | 0 |
Level III [Member] | Other [Member] | ' | ' |
Inventory securities: | ' | ' |
Total inventory securities | 0 | 0 |
Investment securities: | ' | ' |
Total investment securities | 0 | 0 |
Level III [Member] | Mutual funds [Member] | ' | ' |
Investment securities: | ' | ' |
Total investment securities | 0 | 0 |
Level III [Member] | Government and agency obligations [Member] | ' | ' |
Investment securities: | ' | ' |
Total investment securities | 0 | 0 |
Level III [Member] | Unit investment trusts [Member] | ' | ' |
Inventory securities: | ' | ' |
Total inventory securities | ' | 0 |
Level III [Member] | U.S. treasuries [Member] | ' | ' |
Investments segregated under federal regulations: | ' | ' |
Total investments segregated under federal regulations | 0 | 0 |
Level III [Member] | State and municipal obligations [Member] | ' | ' |
Inventory securities: | ' | ' |
Total inventory securities | 0 | 0 |
Level III [Member] | Equities [Member] | ' | ' |
Inventory securities: | ' | ' |
Total inventory securities | 0 | 0 |
Investment securities: | ' | ' |
Total investment securities | 0 | 0 |
Level III [Member] | Corporate bonds and notes [Member] | ' | ' |
Inventory securities: | ' | ' |
Total inventory securities | 0 | 0 |
Level III [Member] | Certificates of deposit [Member] | ' | ' |
Investments segregated under federal regulations: | ' | ' |
Total investments segregated under federal regulations | 0 | 0 |
Inventory securities: | ' | ' |
Total inventory securities | $0 | $0 |