Rental Equipment (Details) - Schedule Of Rental Equipment (USD $) In Thousands, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Schedule Of Rental Equipment [Abstract]
Rental equipment	$ 38,419	$ 38,442	$ 43,252
Less accumulated depreciation	26,369	25,532	27,060
Net rental equipment	$ 12,050	$ 12,910	$ 16,192

Amount before accumulated depreciation, depletion and amortization of other physical assets used in the normal conduct of business to produce goods and services and not intended for resale.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 360

-SubTopic 10

-Section 50

-Paragraph 1

-URI http://asc.fasb.org/extlink&oid=6391035&loc=d3e2868-110229

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