Recent Accounting Developments - Additional Information (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Jan. 01, 2017	Dec. 31, 2014
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Deferred tax assets, valuation allowance		$ 61,456	$ 69,593	$ 89,251		$ 1,044,152
U.S. federal statutory income tax rate		35.00%	35.00%	35.00%
Scenario Forecast [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
U.S. federal statutory income tax rate	21.00%
Adjustments for New Accounting Principle [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Deferred tax assets recorded for previously unrecognized excess tax benefits on share-based payment awards					$ 81,544
Deferred tax assets, valuation allowance					$ 12,090