Income Taxes - Additional Information (Detail) - USD ($)		12 Months Ended
	Dec. 22, 2017	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Tax Disclosure [Abstract]
Net operating loss carryforwards		$ 23,319,000
Valuation allowance		26,445,000	$ 3,071,000
Provisions for US tax reform		46,200,000
Percentage of cash and cash equivalents	15.50%
Percentage of other tax rates	8.00%
Accrued income tax liabilities related to TCJA		32,600,000
Adjustment to corporate tax rate	$ 13,600,000
Uncertain tax positions		18,889,000	5,717,000
Increase in unrecognized tax benefits		16,800,000
Income taxes paid		$ 8,400,000	$ 23,000,000	$ 61,700,000