Derivative Financial Instruments (Narrative) (Details) In Thousands, unless otherwise specified	3 Months Ended									3 Months Ended
	Mar. 31, 2014 USD ($)	Mar. 31, 2013 USD ($)	Dec. 31, 2013 USD ($)	Dec. 31, 2013 EUR (€)	Dec. 31, 2012 USD ($)	Mar. 31, 2014 Interest Rate Swap [Member] Not Designated as Hedging Instrument [Member] USD ($)	Dec. 31, 2013 Foreign Exchange Option [Member] USD ($)	Dec. 31, 2013 Foreign Exchange Option [Member] EUR (€)	Mar. 31, 2014 Cash Flow Hedging [Member] Interest Rate Swap [Member] Designated as Hedging Instrument [Member] USD ($)	Mar. 31, 2014 Interest Expense [Member] USD ($)	Mar. 31, 2013 Interest Expense [Member] USD ($)	Mar. 31, 2014 Interest Expense [Member] Interest Rate Swap [Member] USD ($)	Mar. 31, 2013 Interest Expense [Member] Interest Rate Swap [Member] USD ($)	Mar. 31, 2014 Other Income [Member] Foreign Exchange Option [Member] USD ($)	Mar. 31, 2013 Other Income [Member] Foreign Exchange Option [Member] USD ($)
Derivative [Line Items]
Derivative, Total Notional Amount	$ 679,063					$ 200,000		€ 125,000	$ 479,063
Cash and cash equivalents	159,454	554,948	521,951	250,000	610,970
Prepaid Expense and Other Assets, Current	63,535		65,512				2,577
Gain (Loss) from Components Excluded from Assessment of Cash Flow Hedge Effectiveness, Net										0	0
Gain (Loss) on Cash Flow Hedge Ineffectiveness, Net										0	0
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	$ 2,009	$ (79)										$ 255	$ (79)	$ 1,754	$ 0