Valuation and Qualifying Accounts (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Allowance for Trade Receivables [Member]
Valuation and Qualifying Accounts Disclosure [Line Items]
Valuation Allowances and Reserves, Balance	$ 201,875	$ 202,602	$ 264,105	$ 352,417
Valuation Allowances and Reserves, Charged to Cost and Expense	84,460	99,561	97,995
Valuation Allowances and Reserves, Adjustments	(85,187)	(161,064)	(186,307)
Allowance for Notes Receivable [Member]
Valuation and Qualifying Accounts Disclosure [Line Items]
Valuation Allowances and Reserves, Balance	12,828	13,123	12,562	11,554
Valuation Allowances and Reserves, Charged to Cost and Expense	309	5,851	2,792
Valuation Allowances and Reserves, Adjustments	(604)	(5,290)	(1,784)
Valuation Allowance of Deferred Tax Assets [Member]
Valuation and Qualifying Accounts Disclosure [Line Items]
Valuation Allowances and Reserves, Balance	95,712	24,159	21,037	20,502
Valuation Allowances and Reserves, Charged to Cost and Expense	77,542	5,431	3,765
Valuation Allowances and Reserves, Adjustments	$ (5,989)	$ (2,309)	$ (3,230)

Total of the adjustments in a given period to allowances and reserves, the valuation and qualifying accounts that are either netted against the cost of an asset (in order to value it at its carrying value) or that reflect a liability.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 235

-SubTopic 10

-Section S99

-Paragraph 4

-URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e24092-122690

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 09

-Article 12

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Total of allowances and reserves, the valuation and qualifying accounts that are either netted against the cost of an asset (in order to value it at its carrying value) or that reflect a liability established to represent expected future costs.

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