Basis of Presentation and New Accounting Pronouncements (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2016
Basis Of Presentation And New Accounting Pronouncements [Line Items]
Amount reclassified from prepaid expenses and other assets to other non-current assets		$ 4,390
Scenario, Forecast | ASU 2016-16 | Minimum
Basis Of Presentation And New Accounting Pronouncements [Line Items]
Increase in effective income tax rate	3.00%
Scenario, Forecast | ASU 2016-16 | Maximum
Basis Of Presentation And New Accounting Pronouncements [Line Items]
Increase in effective income tax rate	5.00%