Retirement Benefit Plans - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Pension Plans, Postretirement and Other Employee Benefits [Line Items]
Expense related to defined contribution plan	$ 47,900,000	$ 42,500,000	$ 40,200,000
U.S. and Puerto Rico [Member]
Pension Plans, Postretirement and Other Employee Benefits [Line Items]
Contribution towards defined benefit plans	0
Foreign-based Defined Benefit Plans [Member]
Pension Plans, Postretirement and Other Employee Benefits [Line Items]
Contribution towards defined benefit plans	$ 17,000,000
Minimum [Member] | U.S. and Puerto Rico [Member] | Equity Securities [Member]
Pension Plans, Postretirement and Other Employee Benefits [Line Items]
Target range of assets held by defined benefit plan for cash funds	30.00%
Minimum [Member] | U.S. and Puerto Rico [Member] | Debt Securities [Member]
Pension Plans, Postretirement and Other Employee Benefits [Line Items]
Target range of assets held by defined benefit plan for cash funds	30.00%
Minimum [Member] | U.S. and Puerto Rico [Member] | Non-Traditional Investments [Member]
Pension Plans, Postretirement and Other Employee Benefits [Line Items]
Target range of assets held by defined benefit plan for cash funds	5.00%
Minimum [Member] | Foreign-based Defined Benefit Plans [Member] | Equity Securities [Member]
Pension Plans, Postretirement and Other Employee Benefits [Line Items]
Target range of assets held by defined benefit plan for cash funds	20.00%
Minimum [Member] | Foreign-based Defined Benefit Plans [Member] | Debt Securities [Member]
Pension Plans, Postretirement and Other Employee Benefits [Line Items]
Target range of assets held by defined benefit plan for cash funds	30.00%
Minimum [Member] | Foreign-based Defined Benefit Plans [Member] | Real Estate [Member]
Pension Plans, Postretirement and Other Employee Benefits [Line Items]
Target range of assets held by defined benefit plan for cash funds	15.00%
Minimum [Member] | Foreign-based Defined Benefit Plans [Member] | Cash Fund [Member]
Pension Plans, Postretirement and Other Employee Benefits [Line Items]
Target range of assets held by defined benefit plan for cash funds	3.00%
Minimum [Member] | Foreign-based Defined Benefit Plans [Member] | Other Funds [Member]
Pension Plans, Postretirement and Other Employee Benefits [Line Items]
Target range of assets held by defined benefit plan for cash funds	0.00%
Maximum [Member] | U.S. and Puerto Rico [Member] | Equity Securities [Member]
Pension Plans, Postretirement and Other Employee Benefits [Line Items]
Target range of assets held by defined benefit plan for cash funds	65.00%
Maximum [Member] | U.S. and Puerto Rico [Member] | Debt Securities [Member]
Pension Plans, Postretirement and Other Employee Benefits [Line Items]
Target range of assets held by defined benefit plan for cash funds	50.00%
Maximum [Member] | U.S. and Puerto Rico [Member] | Non-Traditional Investments [Member]
Pension Plans, Postretirement and Other Employee Benefits [Line Items]
Target range of assets held by defined benefit plan for cash funds	15.00%
Maximum [Member] | Foreign-based Defined Benefit Plans [Member] | Equity Securities [Member]
Pension Plans, Postretirement and Other Employee Benefits [Line Items]
Target range of assets held by defined benefit plan for cash funds	37.00%
Maximum [Member] | Foreign-based Defined Benefit Plans [Member] | Debt Securities [Member]
Pension Plans, Postretirement and Other Employee Benefits [Line Items]
Target range of assets held by defined benefit plan for cash funds	50.00%
Maximum [Member] | Foreign-based Defined Benefit Plans [Member] | Real Estate [Member]
Pension Plans, Postretirement and Other Employee Benefits [Line Items]
Target range of assets held by defined benefit plan for cash funds	24.00%
Maximum [Member] | Foreign-based Defined Benefit Plans [Member] | Cash Fund [Member]
Pension Plans, Postretirement and Other Employee Benefits [Line Items]
Target range of assets held by defined benefit plan for cash funds	15.00%
Maximum [Member] | Foreign-based Defined Benefit Plans [Member] | Other Funds [Member]
Pension Plans, Postretirement and Other Employee Benefits [Line Items]
Target range of assets held by defined benefit plan for cash funds	12.00%