Commitments and Contingencies Available Lines of Credit, Outstanding Standby Letter of Credits, and Bonds (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012		Dec. 31, 2011
Line of Credit Facility [Line Items]
Unsecured surety bonds in force	$ 164,820		$ 139,954
Credit Facility [Member]
Line of Credit Facility [Line Items]
Multicurrency revolving line of credit	660,000	[1]	500,000	[1]
Long-term borrowings	140,000	[1]	160,000	[1]
Standby LOCs issued and outstanding	(54,328)	[1]	(44,549)	[1]
Net available for additional borrowings and LOCs	465,672	[1]	295,451	[1]
Unsecured Multicurrency Revolving Lines of Credit [Member]
Line of Credit Facility [Line Items]
Multicurrency revolving line of credit	67,308		67,968
Standby LOCs issued and outstanding	(29,906)		(28,733)
Short-term borrowings(2)	(851)	[2]	0	[2]
Net available for additional borrowings and LOCs	$ 36,551		$ 39,235

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

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