Cash Equivalents, and Investments, Narrative (Details)	3 Months Ended	6 Months Ended
Jun. 30, 2016 USD ($) Investment	Jun. 30, 2015 USD ($)	Jun. 30, 2016 USD ($) Investment	Jun. 30, 2015 USD ($)	Dec. 31, 2015 USD ($) Investment
Cash Equivalents and Investments [Abstract]
Total investments in unrealized loss position \| Investment	214		214		682
Privately-held investments	$ 88,500,000		$ 88,500,000		$ 102,400,000
Privately held investments at fair value	51,400,000		51,400,000		$ 60,200,000
Unrealized gain (loss) on privately-held debt securities	0	$ 0	0	$ 0
Other than temporary impairment of cost method investments	$ 0	$ 0	$ 5,100,000	$ 0

This item represents an other than temporary decline in value that has been recognized against an investment accounted for under the cost method of accounting. The excess of the carrying amount over the fair value of the investment represents the amount of the write down which is or was reflected in earnings. The written down value is a new cost basis with the adjusted value of the investment becoming its new carrying value. Evidence of a loss in value might include, but would not necessarily be limited to, absence of an ability to recover the carrying amount of the investment or inability of the investee to sustain an earnings capacity which would justify the carrying amount of the investment.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 325
-SubTopic 20
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=6872867&loc=d3e40691-111596

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration