Condensed Consolidating Financial Information (Narrative) (Details)	Sep. 30, 2017
6.000% senior secured priority notes due 2019 [Member] | Senior notes [Member]
Condensed Financial Statements, Captions [Line Items]
Debt interest rate (percent)	6.00%
8.500% junior secured priority notes due 2022 [Member] | Junior notes [Member]
Condensed Financial Statements, Captions [Line Items]
Debt interest rate (percent)	8.50%
6.000% senior unsecured notes due 2024 [Member] | Senior unsecured debt [Member]
Condensed Financial Statements, Captions [Line Items]
Debt interest rate (percent)	6.00%
7% senior exchangeable notes due 2017 [Member] | Convertible debt [Member]
Condensed Financial Statements, Captions [Line Items]
Debt interest rate (percent)	7.00%
11.5% senior notes due 2017 [Member] | Senior unsecured debt [Member]
Condensed Financial Statements, Captions [Line Items]
Debt interest rate (percent)	11.50%
4.0% secured note due 2021 [Member] | Secured debt [Member]
Condensed Financial Statements, Captions [Line Items]
Debt interest rate (percent)	4.00%