Income Taxes - Reconciliation of Tax Provision for Continuing Operations (Detail)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2018 Rate	Dec. 31, 2017	Dec. 31, 2017 Rate	Dec. 31, 2016	Dec. 31, 2016 Rate
Income Tax Disclosure [Abstract]
Tax provision at U.S. statutory rate		21.00%		35.00%		35.00%
Tax exempt interest		(5.80%)		(7.80%)		(5.20%)
Foreign tax rate differential		2.70%		(8.60%)		(3.50%)
Valuation allowance on deferred tax assets		(2.40%)		7.20%		1.40%
State and local income tax		1.50%		0.30%		(0.10%)
Tax on undistributed foreign earnings		(1.20%)		(4.80%)		4.90%
One-time tax on foreign earnings - Tax Act		(1.00%)		18.80%		0.00%
Federal deferred taxes remeasurement - Tax Act		0.40%		27.80%		0.00%
U.S. tax on foreign earnings		0.50%		0.30%		4.70%
Audit settlements and unrecognized tax benefits		(0.30%)		(0.80%)		(5.20%)
U.S. permanent items		(0.20%)		(2.20%)		(1.90%)
Italy patent box prior year benefit		0.00%		(1.10%)		0.00%
Other adjustments		(0.40%)		(1.20%)		(0.70%)
Effective income tax rate	14.80%	14.80%	62.90%	62.90%	29.40%	29.40%