Allowance for Credit Losses (Activity in Allowance for Doubtful Accounts) (Details) (USD $) In Thousands, unless otherwise specified	6 Months Ended	12 Months Ended
	Jun. 30, 2013	Dec. 31, 2012
Accounts, Notes, Loans and Financing Receivable [Line Items]
Beginning Balance	$ 133	$ 11
(Reversal of provision) provision	194	122
Ending Balance	327	133
Finance Leases [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Beginning Balance
(Reversal of provision) provision
Ending Balance
Accounts Receivable Allowance for Doubtful Accounts [Member] | Finance Leases [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Beginning Balance		10
(Reversal of provision) provision		(10)
Accounts Receivable Allowance for Doubtful Accounts [Member] | Operating Leases [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Beginning Balance	133	1
(Reversal of provision) provision	194	132
Ending Balance	$ 327	$ 133