Fair Value Measurements (Schedule of Carrying Values and Estimated Fair Values of Debt Instruments) (Details) - USD ($) $ in Thousands	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Jun. 03, 2014
Debt Instrument [Line Items]
Carrying Value	$ 1,014,459				$ 1,025,566
Estimated Fair Value	781,000	$ 854,760	$ 891,290	$ 994,139	1,020,700
8.25% Notes [Member]
Debt Instrument [Line Items]
Senior notes, stated percentage						8.25%
Carrying Value					550,566
Maximum debt redemption rate		35.00%
Estimated Fair Value	306,000	$ 379,760	416,290	519,139	545,700
Intercompany Promissory Note [Member]
Debt Instrument [Line Items]
Estimated Fair Value	325,000	325,000
Revolving Credit Sub-Facility [Member]
Debt Instrument [Line Items]
Carrying Value					475,000
Estimated Fair Value	$ 150,000	$ 150,000	$ 475,000	$ 475,000	$ 475,000