|
Fair Value Table (Detail) (USD $)
In Thousands, unless otherwise specified
|
Mar. 31, 2013
|
Dec. 31, 2012
|
| Securities segregated for regulatory purposes |
$ 2,447,389 |
$ 2,297,024 |
| Financial instruments owned |
3,822,315 |
3,617,879 |
| Financial instruments owned and pledged as collateral |
839,994 |
926,857 |
| Total financial instruments owned |
4,662,309 |
4,544,736 |
| Other investments |
124,839 |
116,232 |
| Total financial assets, at fair value |
7,234,537 |
6,957,992 |
| Financial instruments sold but not yet purchased, at fair value |
4,367,387 |
4,286,260 |
|
Common Stock [Member]
|
|
|
| Financial instruments owned |
999,035 |
887,031 |
| Financial instruments owned and pledged as collateral |
694,338 |
775,222 |
| Other investments |
19,331 |
21,256 |
| Financial instruments sold but not yet purchased, at fair value |
1,801,394 |
1,787,741 |
|
Options [Member]
|
|
|
| Financial instruments owned |
2,477,113 |
2,388,173 |
| Financial instruments sold but not yet purchased, at fair value |
2,464,976 |
2,389,871 |
|
Warrants and discount certificates [Member]
|
|
|
| Financial instruments owned |
153,403 |
147,317 |
| Financial instruments sold but not yet purchased, at fair value |
3,243 |
2,104 |
|
U.S. and Foreign Government Obligations [Member]
|
|
|
| Financial instruments owned |
36,922 |
30,087 |
| Financial instruments owned and pledged as collateral |
142,963 |
146,953 |
| Financial instruments sold but not yet purchased, at fair value |
1,099 |
451 |
|
Warrants [Member]
|
|
|
| Financial instruments owned and pledged as collateral |
614 |
350 |
|
Corporate and municipal bonds [Member]
|
|
|
| Financial instruments owned |
155,842 |
163,920 |
| Financial instruments owned and pledged as collateral |
2,079 |
4,332 |
| Financial instruments sold but not yet purchased, at fair value |
92,245 |
102,543 |
|
Currency forward contracts [Member]
|
|
|
| Financial instruments owned |
0 |
1,351 |
| Financial instruments sold but not yet purchased, at fair value |
4,430 |
3,550 |
|
Other assets - investments [Member]
|
|
|
| Other investments |
105,508 |
94,976 |
|
Level 1
|
|
|
| Securities segregated for regulatory purposes |
2,447,389 |
2,297,024 |
| Financial instruments owned |
3,775,001 |
3,556,995 |
| Financial instruments owned and pledged as collateral |
839,994 |
926,857 |
| Total financial instruments owned |
4,614,995 |
4,483,852 |
| Other investments |
14,925 |
19,956 |
| Total financial assets, at fair value |
7,077,309 |
6,800,832 |
| Financial instruments sold but not yet purchased, at fair value |
4,349,698 |
4,270,877 |
|
Level 1 | Common Stock [Member]
|
|
|
| Financial instruments owned |
999,035 |
887,031 |
| Financial instruments owned and pledged as collateral |
694,338 |
775,222 |
| Other investments |
12,436 |
17,707 |
| Financial instruments sold but not yet purchased, at fair value |
1,801,394 |
1,787,741 |
|
Level 1 | Options [Member]
|
|
|
| Financial instruments owned |
2,477,113 |
2,388,173 |
| Financial instruments sold but not yet purchased, at fair value |
2,464,976 |
2,389,871 |
|
Level 1 | Warrants and discount certificates [Member]
|
|
|
| Financial instruments owned |
153,403 |
147,317 |
| Financial instruments sold but not yet purchased, at fair value |
3,243 |
2,104 |
|
Level 1 | U.S. and Foreign Government Obligations [Member]
|
|
|
| Financial instruments owned |
33,777 |
30,087 |
| Financial instruments owned and pledged as collateral |
142,963 |
146,953 |
| Financial instruments sold but not yet purchased, at fair value |
0 |
451 |
|
Level 1 | Warrants [Member]
|
|
|
| Financial instruments owned and pledged as collateral |
614 |
350 |
|
Level 1 | Corporate and municipal bonds [Member]
|
|
|
| Financial instruments owned |
111,673 |
104,387 |
| Financial instruments owned and pledged as collateral |
2,079 |
4,332 |
| Financial instruments sold but not yet purchased, at fair value |
80,085 |
90,710 |
|
Level 1 | Other assets - investments [Member]
|
|
|
| Other investments |
2,489 |
2,249 |
|
Level 2
|
|
|
| Financial instruments owned |
47,314 |
60,884 |
| Total financial instruments owned |
47,314 |
60,884 |
| Other investments |
109,914 |
96,276 |
| Total financial assets, at fair value |
157,228 |
157,160 |
| Financial instruments sold but not yet purchased, at fair value |
17,689 |
15,383 |
|
Level 2 | Common Stock [Member]
|
|
|
| Other investments |
6,895 |
3,549 |
|
Level 2 | U.S. and Foreign Government Obligations [Member]
|
|
|
| Financial instruments owned |
3,145 |
0 |
| Financial instruments sold but not yet purchased, at fair value |
1,099 |
0 |
|
Level 2 | Corporate and municipal bonds [Member]
|
|
|
| Financial instruments owned |
44,169 |
59,533 |
| Financial instruments sold but not yet purchased, at fair value |
12,160 |
11,833 |
|
Level 2 | Currency forward contracts [Member]
|
|
|
| Financial instruments owned |
0 |
1,351 |
| Financial instruments sold but not yet purchased, at fair value |
4,430 |
3,550 |
|
Level 2 | Other assets - investments [Member]
|
|
|
| Other investments |
103,019 |
92,727 |
|
Level 3
|
|
|
| Total financial assets, at fair value |
0 |
0 |
| Financial instruments sold but not yet purchased, at fair value |
$ 0 |
$ 0 |