Income Taxes - Narrative (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Income Taxes [Line Items]
Operating loss carryforward	$ 2,900,000
Tax credit carryforwards	171,856	$ 120,594
Tax credit carryforwards	1,700,000
Income tax benefit	571,402	31,948	$ (1,056)
Total unrecognized tax benefit	36,789	27,591	27,648	$ 18,440
Unrecognized tax benefits that would impact effective tax rate	6,100
Unrecognized tax benefits, income tax interest and penalties accrued	800	300
Federal
Income Taxes [Line Items]
Tax credit carryforwards	125,700
State
Income Taxes [Line Items]
Tax credit carryforwards	91,700
Foreign Tax Authority
Income Taxes [Line Items]
Valuation allowance (decrease) increase	424,400	(759,700)	$ 106,900
Increase in deferred tax assets related to foreign restructuring		$ 590,000
Revenue Commissioners, Ireland | Foreign Tax Authority
Income Taxes [Line Items]
Income tax benefit	$ 574,200