Quarterly Financial Data - Summary of Quarterly Financial Information (Parenthetical) (Detail) - USD ($) $ in Thousands			3 Months Ended	12 Months Ended
	Jun. 30, 2015	Jun. 25, 2015	Jun. 30, 2015	Dec. 31, 2015
Quarterly Financial Data [Line Items]
Loss on extinguishment of debt				$ (15,528)
Accrued interest paid up to redemption date	$ 3,300
Senior Notes [Member]
Quarterly Financial Data [Line Items]
Loss on extinguishment of debt			$ 15,500	$ (15,500)
Accrued interest paid up to redemption date			3,300
Advisory Services and Monitoring Agreement [Member] | Avista [Member]
Quarterly Financial Data [Line Items]
Aggregate termination fee paid		$ 6,500	$ 6,500