Income Taxes - Components of Deferred Tax Assets and Liabilities (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Current
Accrued liabilities	$ 2,714	$ 1,913
Intangible assets	111	121
Non-qualified stock options	45	0
Other	44orn_DeferredTaxAssetsOtherCurrent	23orn_DeferredTaxAssetsOtherCurrent
Total assets	2,914us-gaap_DeferredTaxAssetsNetCurrent	2,057us-gaap_DeferredTaxAssetsNetCurrent
Long- term
Intangible assets	1,935	2,219
Net operating loss carryforward	3,797	10,604
Non-qualified stock options	1,248	1,268
Foreign tax credits	1,078	0
AMT credits	993	0
Other	(16)orn_DeferredTaxAssetsOtherNoncurrent	1,170orn_DeferredTaxAssetsOtherNoncurrent
Total assets	9,035us-gaap_DeferredTaxAssetsNetNoncurrent	15,261us-gaap_DeferredTaxAssetsNetNoncurrent
Current
Deferred revenue on maintenance contracts	(1,121)	(1,327)
Other	(38)orn_DeferredTaxLiabilitiesOtherCurrent	(4)orn_DeferredTaxLiabilitiesOtherCurrent
Total liabilities	(1,159)	(1,331)
Long- term
Depreciation and amortization	(26,173)	(30,082)
Goodwill	(3,753)	(3,157)
Deferred revenue on maintenance contracts	14	0
Other	0	0
Total liabilities	(29,912)	(33,239)
Net current deferred tax assets	1,755	726
Net non-current deferred tax liabilities	$ 20,877	$ 17,978

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