Sum of the carrying amounts as of the balance sheet date of all assets, excluding assets associated with discontinued operations, that are recognized. Assets are probable future economic benefits obtained or controlled by an entity as a result of past transactions or events.

No definition available.

+ Details

Name:	exh_AssetsExcludingDiscontinuedOperations
Namespace Prefix:	exh_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Aggregate revenue less cost of goods and services sold or operating expenses directly attributable to the revenue generation activity, excluding depreciation and amortization expense. Gross margin is a non-GAAP financial measure.

+ References

No definition available.

+ Details

Name:	exh_GrossMargin
Namespace Prefix:	exh_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Total expenditures for additions to long-lived assets other than financial instruments, long-term customer relationships of a financial institution, mortgage and other servicing rights, deferred policy acquisition costs, and deferred tax assets of the reportable segment; if the amount: (a) is included in the determination of segment assets reviewed by the chief operating decision maker or (b) is otherwise regularly provided to the chief operating decision maker, even if not included in the determination of segment assets.

+ References

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 131

-Paragraph 28

-Subparagraph b

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

+ Details

Name:	us-gaap_AdditionsToNoncurrentAssets
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Total revenue from sale of goods and services rendered during the reporting period, in the normal course of business, reduced by sales returns and allowances, and sales discounts.

+ References

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Article 5

-Section 03

-Paragraph 1

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 225

-SubTopic 10

-Section S99

-Paragraph 2

-Subparagraph (SX 210.5-03.1)

-URI http://asc.fasb.org/extlink&oid=6880815&loc=d3e20235-122688

+ Details

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

- Details

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

Reportable Segments and Geographic Information (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2010	Sep. 30, 2010	Jun. 30, 2010	Mar. 31, 2010	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Sales Information by Geographical Area
Revenue from external customers	$ 702,941	$ 704,478	$ 657,572	$ 618,479	$ 615,780	$ 625,623	$ 643,822	$ 576,308	$ 2,683,470	$ 2,461,533	$ 2,715,601
Total assets	4,356,649				4,741,536				4,356,649	4,741,536	5,234,410
Gross margin									738,060	804,461	915,582
Capital expenditures									282,791	235,990	368,901
North America Contract Operations [Member]
Sales Information by Geographical Area
Revenue from external customers									603,529	608,065	695,315
Total assets	2,052,170				2,061,755				2,052,170	2,061,755	2,357,751
Gross margin									293,460	307,379	396,601
Capital expenditures									192,470	111,087	108,985
International Contract Operations [Member]
Sales Information by Geographical Area
Revenue from external customers									445,059	465,144	391,995
Total assets	887,046				976,700				887,046	976,700	988,257
Gross margin									260,654	289,787	242,742
Capital expenditures									58,767	106,530	236,450
Aftermarket Services [Member]
Sales Information by Geographical Area
Revenue from external customers									409,423	322,097	308,873
Total assets	111,890				160,864				111,890	160,864	148,548
Gross margin									60,761	45,790	62,987
Capital expenditures									2,082	1,348	2,629
Fabrication [Member]
Sales Information by Geographical Area
Revenue from external customers									1,225,459	1,066,227	1,319,418
Total assets	384,099				580,255				384,099	580,255	720,482
Gross margin									123,222	161,505	213,252
Capital expenditures									22,077	12,187	10,592
Reportable Segments [Member]
Sales Information by Geographical Area
Revenue from external customers									2,683,470	2,461,533	2,715,601
Total assets	3,435,205				3,779,574				3,435,205	3,779,574	4,215,038
Gross margin									738,097	804,461	915,582
Capital expenditures									275,396	231,152	358,656
Other [Member]
Sales Information by Geographical Area
Revenue from external customers									0
Total assets	921,444				946,872				921,444	946,872	1,019,372
Gross margin									0
Capital expenditures									$ 7,395	$ 4,838	$ 10,245