Financial Commitments (Reconciliation Of Outstanding Debt Balance To Reported Debt Balance) (Details) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Debt Instrument [Line Items]
Unamortized Discount and Issuance Cost	$ (59,694)	$ (6,697)
Total debt	793,099	817,684
2014 Revolver [Member]
Debt Instrument [Line Items]
Outstanding Long-Term Debt	160,500	158,000
Unamortized Discount and Issuance Cost	(5,157)	(2,185)
Total debt	155,343	155,815
Term Loan [Member]
Debt Instrument [Line Items]
Outstanding Long-Term Debt	80,000	223,750
Unamortized Discount and Issuance Cost	(2,946)	(1,630)
Total debt	77,054	222,120
2010 Senior Notes [Member]
Debt Instrument [Line Items]
Outstanding Long-Term Debt	300,000	300,000
Unamortized Discount and Issuance Cost	(2,133)	(2,882)
Total debt	297,867	297,118
Convertible Notes [Member]
Debt Instrument [Line Items]
Outstanding Long-Term Debt	200,000
Unamortized Discount and Issuance Cost	(49,458)
Total debt	$ 150,542