Marketable Securities (Narrative) (Details) (USD $) | 9 Months Ended | 12 Months Ended | 9 Months Ended | 12 Months Ended | ||||
|---|---|---|---|---|---|---|---|---|
Sep. 30, 2011 | Dec. 31, 2010 | Sep. 30, 2011
U.S. Government Agency And Commercial Paper Securities [Member] | Sep. 30, 2011
SIV Securities [Member] | Sep. 30, 2010
SIV Securities [Member] | Sep. 30, 2011
SEI Private Trust Company [Member] | Sep. 30, 2011
Stanfield Victoria [Member] | Dec. 31, 2010
Stanfield Victoria [Member] | |
| Net unrealized holding gains | $ 2,354,000 | $ 1,339,000 | ||||||
| Unrealized holding gains during the period, income tax expense | 1,383,000 | 784,000 | ||||||
| Debt maturity, minimum | 2020 | |||||||
| Debt maturity, maximum | one year | 2041 | ||||||
| Cumulative losses from SIV securities and SIV-related issues | 140,707,000 | |||||||
| Net gain from SIV securities | 4,128,000 | 29,990,000 | ||||||
| Gains from cash payments received from SIV securities | 8,430,000 | 19,390,000 | ||||||
| Gains or losses from increase/decrease in fair value of SIV securities | (4,302,000) | 10,217,000 | ||||||
| Gain or loss recognized from sale of note | 0 | 0 | ||||||
| Securities owned (Note 6) | $ 20,032,000 | $ 0 | ||||||
| X | ||||||||||
- Definition Cumulative Losses from SIV Securities and SIV Related Issues
|
| X | ||||||||||
- Definition Gain Loss Recognized From the Sale of Senior Note Obligation
|
| X | ||||||||||
- Definition Gains from cash payments received from SIV securities.
|
| X | ||||||||||
- Definition Unrealized Holding Gains During the Period, Income Tax Expense
|
| X | ||||||||||
- Definition When presenting a range of maturity dates, the latest date when the outstanding debt instruments are required to be repaid. May be presented in a variety of ways (for example: year only, month and year, day, month and year, and number of years). Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- Definition When presenting a range of maturity dates, the earliest date when the outstanding debt instruments are required to be repaid. May be presented in a variety of ways (for example: year only, month and year, day, month and year, and number of years). Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- Definition The fair value as of the balance sheet date of firm holdings in debt obligations issued by the US government including short-term Treasury bills, medium-term Treasury notes, and long-term Treasury bonds, as well as debt issued by agencies. Includes both pledged (to counterparties as collateral for financing transactions) and unpledged holdings. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- Definition Gross appreciation or the gross loss in value of the total of unsold available-for-sale securities during the period being reported (except when designated as a fair value hedge). Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- Definition This item represents the gain realized during the period from the sale of trading securities. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|
| X | ||||||||||
- Definition The increases or decreases in the market value of unsold securities whose gains or losses were included in earnings, and which, were not separately or otherwise categorized as trading, available-for-sale, or held-to-maturity. Reference 1: http://www.xbrl.org/2003/role/presentationRef
|