Employee Benefit Plans - Additional Information (Detail)				12 Months Ended
	Dec. 31, 2015 GBP (£)	Jun. 04, 2015 GBP (£)	Mar. 31, 2015 GBP (£) Contributions	Dec. 31, 2015 USD ($)	Dec. 31, 2014 USD ($)	Dec. 31, 2013 USD ($)
Defined Benefit Plan Disclosure [Line Items]
Future contribution to non-U.S. defined benefit pension plans | £			£ 11,200,000
Number of equal contribution | Contributions			3
Amounts paid into the plan from the account security arrangement and additional contributions paid in 2015 in agreement with the Trustee | £	£ 11,200,000	£ 11,200,000
Aggregate amount in account security arrangement					$ 17,500,000
Equity funds managed by LAM				$ 70,444,000	70,490,000
Contributions to employer sponsored defined contribution plans				12,493,000	11,904,000	$ 11,778,000
Other Non-U.S. Pension Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Expected contribution related to the pension plans					$ 10,343,000
U.K. Pension Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Expected contribution related to the pension plans				0
Tranche 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Future contribution date to non-U.S. defined benefit pension plans			Jun. 30, 2015
Tranche 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Future contribution date to non-U.S. defined benefit pension plans			Sep. 30, 2015
Tranche 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Future contribution date to non-U.S. defined benefit pension plans			Dec. 31, 2015
U.S. Pension Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Expected contribution related to the pension plans				$ 0
U.S. Pension Plans [Member] | Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Percentage of plans' assets in debt funds				50.00%	51.00%
U.S. Pension Plans [Member] | Level 1 [Member] | NAV [Member]
Defined Benefit Plan Disclosure [Line Items]
Percentage of plans' assets in equity funds				50.00%	49.00%
Non-U.S. Pension Plans [Member] | NAV [Member] | Debt and Debt Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Percentage of plan assets invested				60.00%	64.00%
Non-U.S. Pension Plans [Member] | Level 1 [Member] | Equities And Equity Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Percentage of plan assets invested				37.00%	34.00%
Non-U.S. Pension Plans [Member] | Level 1 [Member] | Cash And Alternative Investment Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Percentage of plan assets invested				3.00%	2.00%