Summary of Property and Equipment (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
Dec. 31, 2014
Buildings \| Minimum
Property Plant And Equipment [Line Items]
Property and equipment, Useful life	5 years
Buildings \| Maximum
Property Plant And Equipment [Line Items]
Property and equipment, Useful life	50 years
Global Thermoelectric Inc
Property Plant And Equipment [Line Items]
Property and equipment	716
Global Thermoelectric Inc \| Land
Property Plant And Equipment [Line Items]
Property and equipment	15
Property and equipment, Useful life	Indefinite
Global Thermoelectric Inc \| Buildings
Property Plant And Equipment [Line Items]
Property and equipment	81
Property and equipment, Useful life	20 years
Global Thermoelectric Inc \| Leasehold improvements
Property Plant And Equipment [Line Items]
Property and equipment	28
Global Thermoelectric Inc \| Leasehold improvements \| Minimum
Property Plant And Equipment [Line Items]
Property and equipment, Useful life	5 years
Global Thermoelectric Inc \| Leasehold improvements \| Maximum
Property Plant And Equipment [Line Items]
Property and equipment, Useful life	7 years
Global Thermoelectric Inc \| Machinery and Equipment
Property Plant And Equipment [Line Items]
Property and equipment	423
Global Thermoelectric Inc \| Machinery and Equipment \| Minimum
Property Plant And Equipment [Line Items]
Property and equipment, Useful life	2 years
Global Thermoelectric Inc \| Machinery and Equipment \| Maximum
Property Plant And Equipment [Line Items]
Property and equipment, Useful life	5 years
Global Thermoelectric Inc \| Computer Hardware and Software
Property Plant And Equipment [Line Items]
Property and equipment	169
Global Thermoelectric Inc \| Computer Hardware and Software \| Minimum
Property Plant And Equipment [Line Items]
Property and equipment, Useful life	3 years
Global Thermoelectric Inc \| Computer Hardware and Software \| Maximum
Property Plant And Equipment [Line Items]
Property and equipment, Useful life	5 years

The amount of property, plant, and equipment recognized as of the acquisition date.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 805

-SubTopic 20

-Section 50

-Paragraph 1

-Subparagraph (c)

-URI http://asc.fasb.org/extlink&oid=39739317&loc=d3e4845-128472

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 805

-SubTopic 10

-Section 55

-Paragraph 37

-URI http://asc.fasb.org/extlink&oid=35744172&loc=d3e2207-128464

+ Details

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

- Definition

Describes the periods of time over which an entity anticipates to receive utility from its property, plant and equipment (that is, the periods of time over which an entity allocates the initial cost of its property, plant and equipment).

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 235

-SubTopic 10

-Section 50

-Paragraph 3

-URI http://asc.fasb.org/extlink&oid=6367646&loc=d3e18780-107790

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 360

-SubTopic 10

-Section 35

-Paragraph 4

-URI http://asc.fasb.org/extlink&oid=6539997&loc=d3e1205-110223

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Useful life of long lived, physical assets used in the normal conduct of business and not intended for resale, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. Examples include, but not limited to, land, buildings, machinery and equipment, office equipment, furniture and fixtures, and computer equipment.

+ References

No definition available.

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Details

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Namespace Prefix:
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- Details

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Data Type:	na
Balance Type:
Period Type: