Marketable Securities (Trading Securities) (Details) (USD $) In Thousands | 9 Months Ended | 12 Months Ended |
|---|---|---|
Sep. 30, 2011 | Dec. 31, 2010 | |
| Trading Securities, Cost | $ 151,899 | $ 233,075 |
| Trading Securities, Gross Unrealized Gains | 1,448 | 1,900 |
| Trading Securities, Gross Unrealized Losses | (94,217) | (130,381) |
| Trading Securities, Fair Value | 59,130 | 104,594 |
SIV Securities [Member] | ||
| Trading Securities, Cost | 149,850 | 231,026 |
| Trading Securities, Gross Unrealized Gains | 0 | 0 |
| Trading Securities, Gross Unrealized Losses | (94,217) | (130,381) |
| Trading Securities, Fair Value | 55,633 | 100,645 |
LSV-Sponsored Mutual Funds [Member] | ||
| Trading Securities, Cost | 2,049 | 2,049 |
| Trading Securities, Gross Unrealized Gains | 1,448 | 1,900 |
| Trading Securities, Gross Unrealized Losses | 0 | 0 |
| Trading Securities, Fair Value | $ 3,497 | $ 3,949 |
| X | ||||||||||
- Definition All other debt and equity financial instruments, which aren't categorized as available-for-sale, or held-to-maturity and which are not otherwise listed in the existing taxonomy, intended to be held longer than one year from the balance sheet date or the normal operating cycle, if longer. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition This item represents a parenthetical disclosure for the cost of securities classified as trading.
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- Definition The increase (decrease) resulting in a gain from the difference between the fair value and the carrying value, or in the comparative fair values, of trading securities held at each balance sheet date, that was included in earnings for the period. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition The increase (decrease) resulting in a loss from the difference between the fair value and the carrying value, or in the comparative fair values, of trading securities held at each balance sheet date, that was included in earnings for the period. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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