Derivative Instruments (Location and Amounts of Derivative Fair Values On The Condensed Consolidated Balance Sheets) (Details) (Not designated as hedging instruments, USD $) In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Other assets
Derivatives, Fair Value [Line Items]
Asset Derivative Notional Amount	$ 33,875	$ 786,188
Asset Derivative Fair Value	1,274	13,083
Accounts payable and accrued liabilities
Derivatives, Fair Value [Line Items]
Liability Derivative Notional Amount	738,876	162,439
Liability Derivative Fair Value	1,674	5,390
Foreign exchange contracts | Other assets
Derivatives, Fair Value [Line Items]
Asset Derivative Notional Amount	33,875	294,788
Asset Derivative Fair Value	1,274	6,254
Foreign exchange contracts | Accounts payable and accrued liabilities
Derivatives, Fair Value [Line Items]
Liability Derivative Notional Amount	167,376	122,439
Liability Derivative Fair Value	991	1,176
Interest rate swaps | Other assets
Derivatives, Fair Value [Line Items]
Asset Derivative Notional Amount	0	491,400
Asset Derivative Fair Value	0	6,829
Interest rate swaps | Accounts payable and accrued liabilities
Derivatives, Fair Value [Line Items]
Liability Derivative Notional Amount	571,500	40,000
Liability Derivative Fair Value	$ 683	$ 4,214