Summary of Significant Accounting Policies - Reclassifications (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Interest expense	$ 6,219	$ 5,440	$ 12,098	$ 11,301
Loss on extinguishment of debt	$ (11,883)	$ 0	$ (11,883)	(326)
Reclassification [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Interest expense				(300)
Loss on extinguishment of debt				$ 300