Debt (Credit Facility) (Narrative) (Details) (USD $)	3 Months Ended		0 Months Ended	3 Months Ended		0 Months Ended	3 Months Ended					0 Months Ended		3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012	Mar. 26, 2013 Revolving Credit Facility And Together With Term Loan Facilities 2011 Credit Facility [Member]	Mar. 31, 2013 Revolving Credit Facility And Together With Term Loan Facilities 2011 Credit Facility [Member]	Jun. 17, 2011 Revolving Credit Facility And Together With Term Loan Facilities 2011 Credit Facility [Member]	Jun. 17, 2011 2013 Credit Facility [Member]	Mar. 31, 2013 2013 Credit Facility [Member]	Mar. 31, 2012 2013 Credit Facility [Member]	Mar. 31, 2012 2011 Credit Facility [Member]	Mar. 31, 2013 Term Loan A Facility Due 2018 [Member]	Mar. 15, 2013 Term Loan A Facility Due 2018 [Member]	Mar. 26, 2013 Term Loan B Facility Due 2018 [Member]	Mar. 15, 2013 Term Loan B Facility Due 2018 [Member]	Mar. 31, 2013 Minimum [Member] 2011 Credit Facility [Member]	Mar. 31, 2013 Maximum [Member] 2013 Credit Facility [Member]	Mar. 31, 2013 Maximum [Member] 2011 Credit Facility [Member]	Mar. 31, 2013 LIBOR Rate [Member] Term Loan B Facility Due 2018 [Member] 2013 Credit Facility [Member]	Mar. 31, 2013 LIBOR Rate [Member] Minimum [Member] 2013 Credit Facility [Member]	Mar. 31, 2013 LIBOR Rate [Member] Maximum [Member] 2013 Credit Facility [Member]	Mar. 31, 2013 Alternate Base Rate [Member] Term Loan B Facility Due 2018 [Member] 2011 Credit Facility [Member]	Mar. 31, 2013 Alternate Base Rate [Member] Minimum [Member] 2013 Credit Facility [Member]	Mar. 31, 2013 Alternate Base Rate [Member] Maximum [Member] 2013 Credit Facility [Member]
Line of Credit Facility [Line Items]
Revolving credit facility, borrowing capacity					$ 500,000,000
Amount outstanding											1,387,500,000		60,600,000
Maximum leverage ratio	3.75
Minimum interest coverage ratio	3.50
Long term debt, term				5 years						5 years
Additional borrowings						500,000,000
Margin rate over base rate																		1.75%	2.50%	2.00%	0.75%	1.50%
Commitment fee basis points														0.00375		0.0050
Payments and accruals of deferred financing costs							8,100,000
Payments of financing costs	7,251,000	0					7,600,000
Description of variable rate basis															LIBOR	LIBOR
LIBOR margin																	3.00%
Repayments of Long-term Debt												100,000,000
License agreement term extension			2 years
Net loss on extinguishment of debt	$ (11,312,000)	$ (5,426,000)						$ 500,000	$ 8,600,000			$ 2,200,000