Debt Schedule of Long-Term Debt Repayments (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012		Dec. 31, 2011		Dec. 31, 2010
Debt Instrument [Line Items]
Repayments of Long-term Debt	$ 115,002		$ 848,054		$ 155,163
2011 Senior Secured Credit Facility [Member]
Debt Instrument [Line Items]
Repayments of Long-term Debt	15,002		7,500		0
2007 Senior Secured Credit Facility [Member]
Debt Instrument [Line Items]
Repayments of Long-term Debt	0		406,950		155,163
Secured Debt [Member] | Credit Facilities [Member]
Debt Instrument [Line Items]
Repayments of Long-term Debt	115,002		624,450		155,163
Line of Credit [Member] | 2011 Senior Secured Credit Facility [Member]
Debt Instrument [Line Items]
Repayments of Long-term Debt	100,000	[1]	40,000		0
Line of Credit [Member] | 2007 Senior Secured Credit Facility [Member]
Debt Instrument [Line Items]
Repayments of Long-term Debt	$ 0	[2]	$ 170,000	[2]	$ 0	[2]

[1] We borrowed $80.0 million under the multicurrency revolving line of credit during 2012.

[2] See repayment of the convertible senior subordinated notes below.