Fair Value Non-recurring measurement (Details 4) (Fair Value, Measurements, Nonrecurring, Level 3, USD $) In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Fair Value, Measurements, Nonrecurring \| Level 3
Non-recurring fair value measurements
Cost Method Investments, Fair Value Disclosure	$ 9,242	$ 0

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