Commitments and Contingencies Available Lines of Credit, Outstanding Standby Letter of Credits, and Bonds (Details) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2013		Dec. 31, 2012
Line of Credit Facility [Line Items]
Multicurrency revolving line of credit	$ 660,000
Credit Facility [Member]
Line of Credit Facility [Line Items]
Multicurrency revolving line of credit	660,000	[1]	660,000	[1]
Long-term borrowings	(140,000)	[1]	(140,000)	[1]
Standby LOCs issued and outstanding	(47,037)	[1]	(54,328)	[1]
Net available for additional borrowings and LOCs	472,963	[1]	465,672	[1]
Unsecured Multicurrency Revolving Lines of Credit [Member]
Line of Credit Facility [Line Items]
Multicurrency revolving line of credit	97,456		67,308
Standby LOCs issued and outstanding	(29,581)		(29,906)
Net available for additional borrowings and LOCs	65,144		36,551
Short-term borrowings(2)	(2,731)	[2]	(851)	[2]
Surety Bond [Member]
Line of Credit Facility [Line Items]
Unsecured surety bonds in force	$ 136,934		$ 164,820

[1] See Note 6 for details regarding our secured credit facilities.

[2] Short-term borrowings are included in "Other current liabilities" on the Consolidated Balance Sheets.