Commitments and Contingencies - Additional Information (Detail) - USD ($) $ in Millions		3 Months Ended		6 Months Ended
	Sep. 23, 2015	Jun. 30, 2017	Mar. 31, 2017	Jun. 30, 2017
Commitments and Contingencies [Line Items]
Loss Contingency, name of plaintiff			Baldwin Hackett & Meeks, Inc.
Loss contingency, damages sought, value	$ 43.8
Loss contingency, damages awarded, value			$ 43.8
BHMI judgment and related fees and interest expense		$ 48.1	$ 2.7	$ 48.1
General and Administrative Expense [Member]
Commitments and Contingencies [Line Items]
BHMI judgment and related fees and interest expense		46.7		46.7
Interest Expense [Member]
Commitments and Contingencies [Line Items]
BHMI judgment and related fees and interest expense		$ 1.4		$ 1.4