The cash outflow to acquire equity securities classified as available-for-sale securities, because they are not classified as trading securities.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Glossary Investing Activities
-URI http://asc.fasb.org/extlink&oid=6516133

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 13
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=66902209&loc=d3e3213-108585

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 45
-Paragraph 11
-URI http://asc.fasb.org/extlink&oid=66010992&loc=d3e26853-111562

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

Commitments and Contingencies (Details 2) - Private equity fund € in Millions, $ in Millions	1 Months Ended
	May 31, 2017 EUR (€)	May 31, 2017 USD ($)	Apr. 29, 2017 EUR (€)	Apr. 29, 2017 USD ($)
Investment commitments
Unfunded commitment to invest in private equity fund			€ 5.0	$ 5.4
Subsequent Events
Investment commitments
Funded portion of the commitment to invest in private equity fund	€ 0.5	$ 0.5