The Company - Additional Information (Detail) - USD ($)	1 Months Ended		6 Months Ended		12 Months Ended
	May 31, 2017	Mar. 31, 2016	Jun. 30, 2018	Dec. 31, 2017	Jun. 30, 2018	Jun. 30, 2017
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Effective Income Tax Rate				35.00%
Remeasurement of deferred tax balance, amount				$ 13,600,000
Tax Cuts and Jobs Act 2017, Accounting Complete				false
Unrecognized tax benefits				$ 0		$ 0
Accounting Standards Update 2016-09 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Impact of adopted accounting standard		did not have a material effect on our financial statements
Accounting Standards Update 2017-09 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Impact of adopted accounting standard	did not have a material effect on our financial statements
Scenario, Forecast
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Effective Income Tax Rate			21.00%		28.10%