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Significant Accounting Policies (Detail) (USD $)
In Thousands, unless otherwise specified |
3 Months Ended | ||
|---|---|---|---|
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Mar. 31, 2013
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Dec. 31, 2012
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May 03, 2007
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| Significant accounting policies | |||
| SIP expense - Year of grant | 50.00% | ||
| SIP expense - Remaining vesting period | 50.00% | ||
| SIP expense - Employees over fifty nine in year of grant | 100.00% | ||
| Over 59 percent of shares eligible | 100.00% | ||
| Percent of shares forfeited post employment | 50.00% | ||
| U.S. Treasury Bills | $ 2,447,400 | $ 2,297,000 | |
| Securities Purchased Under Agreement to Resell Segregated for Regulatory Purposes | 6,460,000 | 6,370,000 | |
| Equity method investments | 26,000 | 34,700 | |
| Cost method investments | $ 27,200 | $ 36,200 | |
| Property and equipment useful lives | Computer equipment is depreciated over three to five years and office furniture and equipment are depreciated over five to seven years. Qualifying costs for internally developed software are capitalized and amortized over the expected useful life of the developed software, not to exceed three years. | ||
| Lease commitments as a percentage of total assets. | 0.10% |
| X | ||||||||||
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- Definition
This item represents the carrying amount on the entity's balance sheet of its investment in common stock and member interests in limited liability companies and partnerships of an equity method investee. This is not an indicator of the fair value of the investment, rather it is the initial cost adjusted for the entity's share of earnings and losses of the investee, adjusted for any distributions (dividends) and other than temporary impairment (OTTI) losses recognized. No definition available.
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- Definition
Existing lease commitments as a percentage of total assets. No definition available.
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- Definition
Percentage of unvested shares to be received by employees over the age of 59 who discontinue employment with the Company without cause and continue to meet the terms of the plans' post-employment provisions. No definition available.
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- Definition
Percentage of unvested shares forfeited by employees who discontinue employment with the Company without cause and continue to meet the terms of the plans' post-employment provisions. No definition available.
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- Definition
The carrying value of funds, segregated for regulatory purposes and for the exclusive benefit of customers, outstanding loaned in the form of security resale agreements if the agreement requires the purchaser to resell the identical security purchased or a security that meets the definition of "substantially the same" in the case of a dollar roll. Also includes purchases of participations in pools of securities that are subject to a resale agreement. No definition available.
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- Definition
Percent of fair value of stock grant expensed during the first year of the grant for employees who are over fifty nine years old. No definition available.
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- Definition
Percent of fair value of stock grant expensed after the first year of the grant. No definition available.
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| X | ||||||||||
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- Definition
Percent of fair value of stock grant expensed in the year of the grant. No definition available.
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- Details
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- Definition
This item represents the aggregate carrying amount of all cost-method investments as reported on or included in the balance sheet. The original cost of the investments may differ from the aggregate carrying amount disclosed due to various adjustments such as: (i) dividends received in excess of earnings after the date of investment that are considered a return of investment and therefore recorded as reductions to cost of the investment, or (ii) a series of operating losses of an investee or other factors which may indicate that a decrease in value of the investment has occurred which is other than temporary and accordingly such decrease in value has been recognized. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- 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
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| X | ||||||||||
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- Definition
Describes the periods of time over which an entity anticipates to receive utility from its property, plant and equipment (that is, the periods of time over which an entity allocates the initial cost of its property, plant and equipment). Reference 1: http://www.xbrl.org/2003/role/presentationRef
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