Fair Value Non-recurring measurement (Details 4) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Fair Value, Measurements, Nonrecurring \| Level 3
Non-recurring fair value measurements
Cost Method Investments, Fair Value Disclosure	$ 0	$ 9,242

Fair value portion of investments accounted under the cost method.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 325
-SubTopic 20
-Section 25
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=29638263&loc=d3e39828-111592

Name:	us-gaap_CostMethodInvestmentsFairValueDisclosure
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant