Debt - 8.25% Senior Secured Notes (Details) - Senior Secured Notes - USD ($)					2 Months Ended	4 Months Ended	12 Months Ended
	Mar. 13, 2015	Mar. 10, 2015	Jul. 01, 2013	Jun. 05, 2013	Jun. 15, 2015	Apr. 13, 2015	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2016	Jun. 30, 2016	Sep. 30, 2015
Debt Instrument [Line Items]
Writedown of capitalized debt costs								$ 9,600,000
8.25% Senior Secured Notes
Debt Instrument [Line Items]
Interest rate (percent)	8.25%		8.25%	8.25%			8.25%		8.25%		8.25%
Aggregate principal amount	$ 305,000,000.0			$ 305,000,000.0			$ 305,000,000.0
Escrow agent fees and expenses			$ 3,000,000
Redemption notice, period	30 days
Funds held in escrow	$ 330,200,000										$ 330,200,000
Accrued interest for the period						$ 8,200,000
Make-whole premium percentage						4.125%
Debt make-whole premium					$ 16,500,000		16,500,000
Other miscellaneous charges					$ 400,000
Writedown of capitalized debt costs							$ 8,500,000
8.25% Senior Secured Notes | Prior to June 15, 2015
Debt Instrument [Line Items]
Redemption price percentage				100.00%
6.875% Senior Secured Notes
Debt Instrument [Line Items]
Interest rate (percent)	6.875%	6.875%					6.875%		6.875%	6.875%
Redemption price percentage		106.875%