Subsequent Event - Additional Information (Details) (USD $) In Millions, unless otherwise specified		0 Months Ended
Jun. 30, 2014 ZCEL	Jul. 07, 2014 ZCEL Subsequent Event	Jun. 30, 2014 Chengdu Ya Guang Electric Company Limited
Subsequent Event [Line Items]
Equity ownership percentage	33.00%	95.00%	5.00%
Increase in additional ownership percentage		62.00%
Cash paid for additional ownership		$ 4

The cash outflow associated with the acquisition of business during the period. The cash portion only of the acquisition price.

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=31042434&loc=d3e3213-108585

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