Supplemental Guarantor Information (Narrative) (Details) - USD ($)	1 Months Ended
	Jan. 31, 2017	Oct. 31, 2015	Apr. 30, 2015	Feb. 28, 2015	May 31, 2014
Initial Senior Notes [Member]
Debt Instrument [Line Items]
Principal amount					$ 200,000,000
Interest rate					6.875%
Maturity year					2022
Initial Exchange Notes [Member]
Debt Instrument [Line Items]
Principal amount				$ 200,000,000
Interest rate				6.875%
Maturity year				2022
April 2015 Senior Notes [Member]
Debt Instrument [Line Items]
Principal amount			$ 60,000,000
Interest rate			6.875%
Maturity year			2022
January 2017 Senior Notes [Member]
Debt Instrument [Line Items]
Principal amount	$ 125,000,000
Interest rate	6.875%
Maturity year	2022
October 2015 Exchange Notes [Member]
Debt Instrument [Line Items]
Principal amount		$ 60,000,000
Interest rate		6.875%
Maturity year		2022