Financial Commitments (Summary Of Interest Expense As Reported In The Condensed Consolidated Statements of Operations) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Other interest	$ 831	$ 863	$ 1,693	$ 2,199
Cash portion of loss on extinguishment	1,913		1,913
Non-cash portion of loss on extinguishment	5,139		5,139
Total cash interest expense	14,405	13,873	26,133	26,266
Total non-cash interest expense	8,114	1,661	11,950	3,348
Total cash and non-cash interest expense	22,519	15,534	38,083	29,614
2017 Senior Notes [Member]
Interest on debt	6,780		6,780
Total non-cash interest expense	$ 141		$ 141
Effective interest rates	7.13%		7.13%
2010 Senior Notes [Member]
Interest on debt	$ 1,207	5,719	$ 6,926	11,438
Total non-cash interest expense	54	250	308	498
Convertible Notes [Member]
Interest on debt	1,437	240	2,875	240
Total non-cash interest expense	$ 2,214	340	$ 4,378	340
Effective interest rates	9.39%		9.39%
2017 Credit Facility [Member]
Interest on debt	$ 1,491		$ 1,491
Total non-cash interest expense	281		281
2014 Credit Facility [Member]
Interest on debt	746	7,051	4,455	12,389
Total non-cash interest expense	$ 285	$ 1,071	$ 1,703	$ 2,510