Long-Term Debt (Schedule of Early Redemption Prices on 8.0% Senior Notes) (Details) - Debt Instrument, Redemption, Period Five [Member] - Senior Notes at 8.0, Due 2019 [Member] - Senior Notes [Member]	3 Months Ended
	Mar. 31, 2018
Debt Instrument, Redemption [Line Items]
Debt Instrument Redemption Price Percentage	100.00%
Debt Instrument, Redemption Period, Start Date	Nov. 15, 2017
Debt Instrument, Redemption Period, End Date	Nov. 14, 2019