Net investment in sales-type leases (Schedule of minimum lease payments under sales-type leases) (Details) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2012
Leases [Abstract]
2012 (remaining six months)	$ 289
2013	578
2014	578
2015	143
2016 and thereafter	0
Total	$ 1,588

Amount of minimum lease payments to be received by the lessor for capital leases.

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

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-Name Accounting Standards Codification

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-Section 50

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Amount of minimum lease payments to be received by the lessor in the fifth fiscal year following the latest fiscal year for capital leases.

+ References

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Amount of minimum lease payments to be received by the lessor in the fourth fiscal year following the latest fiscal year for capital leases.

+ References

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

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Amount of minimum lease payments to be received by the lessor in the third fiscal year following the latest fiscal year for capital leases.

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

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Amount of minimum lease payments to be received by the lessor in the second fiscal year following the latest fiscal year for capital leases.

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

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Amount of minimum lease payments to be received by the lessor in the remainder of the fiscal year following the latest fiscal year ended for capital leases.

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