Financial Commitments (Summary Of Interest Expense As Reported In The Condensed Consolidated Statements of Operations) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Other interest	$ 802	$ 556	$ 2,495	$ 2,755
Cash portion of loss on extinguishment			1,913
Non-cash portion of loss on extinguishment			5,139
Total cash interest expense	12,868	11,266	39,001	37,531
Total non-cash interest expense	2,775	3,775	14,725	7,124
Total interest expense	15,643	15,041	53,726	44,655
2017 Senior Notes [Member]
Interest on debt	8,593		15,373
Total non-cash interest expense	$ 185		$ 326
Effective interest rates	7.13%		7.13%
2010 Senior Notes [Member]
Interest on debt		5,719	$ 6,926	17,156
Total non-cash interest expense		251	308	750
Convertible Notes [Member]
Interest on debt	$ 1,438	1,438	4,313	1,677
Total non-cash interest expense	$ 2,268	2,066	$ 6,646	2,405
Effective interest rates	9.39%		9.39%
2017 Credit Facility [Member]
Interest on debt	$ 2,035		$ 3,526
Total non-cash interest expense	$ 322		603
2014 Credit Facility [Member]
Interest on debt		3,553	4,455	15,943
Total non-cash interest expense		$ 1,458	$ 1,703	$ 3,969