Summary of Investments - SOI Ltd partnership Sec lending Special deposits (Details 5) - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015
Investments, Debt and Equity Securities [Abstract]
Limited partnership and other corporation interests	$ 37,077	$ 40,980
Nature and activities of the VIEs and the effect on financial statements
Carrying value in relation to the activities of the VIEs	34,601	38,504
Maximum exposure to loss in relation to the activities of the VIEs	34,601	38,504
Special deposits and securities lending
Fair value of securities on deposit with governmental authorities	7,014	14,000
Securities loaned to third parties at amortized cost	169,660	0
Estimated fair value of securities loaned to third parties	167,578	0
Restricted cash received as collateral	107,654	0
Securities received as collateral	64,776	0
Maturity Overnight and Continuous
Transfer of certain financial assets accounted for as secured borrowings
Securities lending transactions	167,578	0
Maturity Overnight and Continuous \| U.S. government direct obligations and U.S. agencies
Transfer of certain financial assets accounted for as secured borrowings
Securities lending transactions	7,091	0
Maturity Overnight and Continuous \| Corporate debt securities
Transfer of certain financial assets accounted for as secured borrowings
Securities lending transactions	$ 160,487	$ 0

Fair value of securities loaned to other entities.

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Amount of cash subject to withdrawal restrictions, restricted deposits held as compensating balances, and cash and securities segregated in compliance with regulations (such as cash deposited in a special reserve account for the exclusive benefit of customers).

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The amount of cash received as security in return for loaning securities to another party.

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Total investments in (A) an entity in which the entity has significant influence, but does not have control, (B) subsidiaries that are not required to be consolidated and are accounted for using the equity and or cost method, and (C) an entity in which the reporting entity shares control of the entity with another party or group. Includes long-term advances receivable from a party that is affiliated with the reporting entity by means of direct or indirect ownership.

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Amount, after the effects of master netting arrangements, of securities loaned to entities in exchange for collateral. Includes liabilities not subject to a master netting arrangement and not elected to be offset.

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Amount, before effects of master netting arrangements, of financial assets loaned to entities in exchange for collateral. Includes liabilities not subject to a master netting arrangement and financial assets transferred other than securities that qualify as secured borrowings.

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The carrying amount of the consolidated Variable Interest Entity's assets included in the reporting entity's statement of financial position.

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The reporting entity's maximum amount of exposure to loss as a result of its involvement with the Variable Interest Entity (VIE).

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