Income Taxes - Schedule of Reconciliation of Federal Statutory Rate to Effective Income Tax Rate (Detail)	6 Months Ended		12 Months Ended
	Jun. 30, 2018	Dec. 31, 2017	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2018
Income Tax Disclosure [Abstract]
Tax expense (benefit) at federal statutory rate	21.00%	35.00%	21.00%	21.00%	28.06%
State taxes, net of federal benefit			5.50%	(11.10%)	5.50%
Change in valuation allowance			(32.80%)	3.70%	(168.90%)
Non-deductible executive compensation			(28.30%)	48.40%	90.30%
Changes in uncertain tax positions			(13.60%)	2.00%	12.90%
Foreign branch operations, net of foreign tax deductions			(8.80%)	9.70%	91.20%
Non-deductible other expenses			(5.20%)	6.10%	39.20%
Non-deductible acquisition costs			(0.10%)	7.20%	26.00%
Changes in tax laws or rates			4.70%	(10.80%)	(738.70%)
Tax rate differential on foreign earnings			7.30%	(4.50%)	(50.70%)
Research and development credit			11.10%	(14.80%)	(33.40%)
Share-based payments			15.30%	(94.00%)	(33.40%)
Other			(0.80%)	0.30%	2.60%
Effective income tax rate, continuing operations			(24.70%)	(36.80%)	(729.30%)