Income Taxes - Reconciliation of Income Taxes at Statutory Rate (Detail) - USD ($)	3 Months Ended		12 Months Ended
	Mar. 31, 2018	Dec. 31, 2017	Mar. 31, 2018	Mar. 31, 2017	Mar. 31, 2016
Income Tax Disclosure [Abstract]
United States statutory income tax expense			$ 75,196,000	$ 74,444,000	$ 63,678,000
Impact of Tax Act	$ 4,106,000	$ 77,347,000	83,400,000	0	0
State income taxes, net of federal effect			3,146,000	3,677,000	3,282,000
Nondeductible expenses, domestic manufacturing deduction and other			1,078,000	1,993,000	(1,407,000)
Legal proceedings charge - European Competition Investigations - See Note 18			0	7,873,000	668,000
Goodwill impairment - See Note 5			0	3,812,000	6,475,000
Effect of foreign operations			(35,048,000)	(39,377,000)	(28,845,000)
Valuation allowance			(9,279,000)	2,050,000	6,262,000
Income tax expense			$ 118,493,000	$ 54,472,000	$ 50,113,000