Foreign Currency Translation (Details) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2012	Dec. 31, 2011
Summary of impact of translating financial statements of Company's international subsidiaries
Accumulated other comprehensive Income (Loss)	$ (36,387)	$ (23,682)
Total Assets of the Company's Subsidiaries	3,581,318	3,522,408
Brazil [Member]
Summary of impact of translating financial statements of Company's international subsidiaries
Exchange Rate	2.03	1.87
Accumulated other comprehensive Income (Loss)	(19,595)
Total Assets of the Company's Subsidiaries	318,834
Mexico[Member]
Summary of impact of translating financial statements of Company's international subsidiaries
Exchange Rate	12.88	14.00
Accumulated other comprehensive Income (Loss)	6,716
Total Assets of the Company's Subsidiaries	136,039
Chile [Member]
Summary of impact of translating financial statements of Company's international subsidiaries
Exchange Rate	474.50	520.70
Accumulated other comprehensive Income (Loss)	3,422
Total Assets of the Company's Subsidiaries	51,584
All other [Member]
Summary of impact of translating financial statements of Company's international subsidiaries
Exchange Rate
Accumulated other comprehensive Income (Loss)	1,084
Total Assets of the Company's Subsidiaries
Argentina [Member]
Summary of impact of translating financial statements of Company's international subsidiaries
Exchange Rate	4.74	4.31
Accumulated other comprehensive Income (Loss)	(9,688)
Total Assets of the Company's Subsidiaries	133,889
Colombia [Member]
Summary of impact of translating financial statements of Company's international subsidiaries
Exchange Rate	1,800.52	1,950.00
Accumulated other comprehensive Income (Loss)	2,157
Total Assets of the Company's Subsidiaries	$ 43,440

Accumulated change in equity from transactions and other events and circumstances from non-owner sources, net of tax effect, at period end. Excludes Net Income (Loss), and accumulated changes in equity from transactions resulting from investments by owners and distributions to owners. Includes foreign currency translation items, certain pension adjustments, unrealized gains and losses on certain investments in debt and equity securities, other than temporary impairment (OTTI) losses related to factors other than credit losses on available-for-sale and held-to-maturity debt securities that an entity does not intend to sell and it is not more likely than not that the entity will be required to sell before recovery of the amortized cost basis, as well as changes in the fair value of derivatives related to the effective portion of a designated cash flow hedge.

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 130

-Paragraph 14, 17, 26

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 220

-SubTopic 10

-Section 45

-Paragraph 11

-URI http://asc.fasb.org/extlink&oid=20435746&loc=d3e637-108580

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 220

-SubTopic 10

-Section 45

-Paragraph 14A

-URI http://asc.fasb.org/extlink&oid=20435746&loc=SL7669686-108580

Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 220

-SubTopic 10

-Section 45

-Paragraph 14

-URI http://asc.fasb.org/extlink&oid=20435746&loc=d3e681-108580

Reference 5: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 04

-Article 3

Reference 6: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 31

-Article 5

Reference 7: http://www.xbrl.org/2003/role/presentationRef

-Publisher AICPA

-Name Accounting Principles Board Opinion (APB)

-Number 12

-Paragraph 10

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 8: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name FASB Staff Position (FSP)

-Number FAS115-1/124-1

-Paragraph 15D

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

+ Details

- Definition

Sum of the carrying amounts as of the balance sheet date of all assets that are recognized. Assets are probable future economic benefits obtained or controlled by an entity as a result of past transactions or events.

+ References+ Details