Accounts and Notes Receivable and Credit Quality of Notes Receivable - Modification of Terms (Details) (Notes Receivable, USD $)	3 Months Ended
	Mar. 31, 2014 contract customer
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of Customers	3
Number of Notes	9
Pre-Modification Investment	$ 7.0
Post-Modification Investment	7.0
International
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of Customers	3
Number of Notes	9
Pre-Modification Investment	7.0
Post-Modification Investment	7.0
International | Customer One [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of Customers	1
Post-Modification Investment	3,100,000
Number of notes consolidated into one	3
Contract extension term	4 months
International | Customer Two [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of Customers	1
Post-Modification Investment	2,300,000
Contract extension term	9 months
International | Customer Three [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of Customers	1
International | Customer Three, Note One [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Post-Modification Investment	1,400,000
Number of notes consolidated into one	4
Contract extension term	5 months
International | Customer Three, Note Two [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Post-Modification Investment	$ 200,000
Contract extension term	7 months