Consolidated Company-Sponsored Investment Funds (Change in Carrying Value Associated with Level 3 Financial Instruments) (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Fair value measurement Level 3 reconciliation [Abstract]
Balance as of beginning of period	$ 117	$ 117	$ 142	$ 1,071
Purchases	0	0	0	0
Sales	0	0	0	0
Realized gains (losses), net	0	0	0	0
Unrealized gains (losses), net	1	0	(24)	(954)
Balance as of end of period	118	117	118	117
Company-sponsored investment funds
Fair value measurement Level 3 reconciliation [Abstract]
Balance as of beginning of period	11,834	5,871	8,373	2,264
Transfers (out) in	(3,602)	(406)	(3,788)	(82)
Purchases	1,187	1,247	8,978	7,381
Sales	(2,996)	(197)	(7,345)	(2,820)
Realized gains (losses), net	12	2	35	(97)
Unrealized gains (losses), net	(40)	(25)	129	(158)
Accrued discounts	6	2	19	6
Balance as of end of period	$ 6,401	$ 6,494	$ 6,401	$ 6,494

Amount of unrealized gain (loss) recognized in income from asset measured at fair value on recurring basis using unobservable input (level 3) and still held.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (d)
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A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

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Amount of gain (loss) recognized in income from asset measured at fair value on recurring basis using unobservable input (level 3).

+ References

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-Publisher FASB
-Name Accounting Standards Codification
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-Section 50
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Amount of purchases of financial instrument classified as an asset measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.

+ References

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Amount of sale of financial instrument classified as an asset measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.

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Amount of transfer of financial instrument classified as an asset into (out of) level 3 of the fair value hierarchy.

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Fair value of financial instrument classified as an asset measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.

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Amount of accretion (amortization) of purchase discount (premium) on nonoperating securities.

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