Fair Value Measurements - Investments in Company-Sponsored Funds (Details) $ in Thousands	12 Months Ended
Dec. 31, 2018 USD ($)
Investment Holdings [Line Items]
Fair Value	$ 6,504
Unfunded Commitments	1,399
Hedge Funds [Member]
Investment Holdings [Line Items]
Fair Value	1,596
Unfunded Commitments	$ 0
Redemption Frequency	Quarterly - Annually
Private Equity Funds
Investment Holdings [Line Items]
Investments Lock In Period	10 years
Fair Value	$ 4,908
Unfunded Commitments	$ 1,399

Investment redemption frequency.

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- Definition

Investments lock in period.

+ References

No definition available.

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- Definition

The amount of unfunded commitments for which the entity is obligated, to those certain investments for which net asset value per share is calculated (including by unit, membership interest, or other equity (ownership interest) unit measure) (alternative investments).

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 6A
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=99377789&loc=SL6742756-110258

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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

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- Definition

Fair value portion of investment securities, including, but not limited to, marketable securities, derivative financial instruments, and investments accounted for under the equity method.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=99377789&loc=d3e19207-110258

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