Consolidated Company-Sponsored Investment Funds (Change in Carrying Value Associated with Level 3 Financial Instruments) (Details) - USD ($) $ in Thousands	3 Months Ended
Mar. 31, 2019	Mar. 31, 2018
Fair value measurement Level 3 reconciliation [Abstract]
Balance as of beginning of period	$ 142	$ 1,071
Purchases	0	0
Sales	0	0
Realized gains (losses), net	0	0
Unrealized (losses) gains, net	(27)	0
Balance as of end of period	115	1,071
Company-sponsored investment funds
Fair value measurement Level 3 reconciliation [Abstract]
Balance as of beginning of period	8,373	2,264
Transfers (out) in	(97)	(13)
Purchases	2,111	4,034
Sales	(284)	(333)
Realized gains (losses), net	2	5
Unrealized (losses) gains, net	149	(58)
Accrued discounts	7	2
Balance as of end of period	$ 10,261	$ 5,901

Amount of unrealized (holding) gain (loss) which is included in the statement of income (or changes in net assets) related to those assets still held at the reporting date for which fair value is measured on a recurring basis using significant unobservable inputs (Level 3).

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-Publisher FASB
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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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- Definition

Amount of gain (loss) recognized in the income statement for 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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- Definition

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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-Publisher FASB
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- Definition

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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- Definition

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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- Definition

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

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-Publisher FASB
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