Short and Long-Term Debt - Long-Term Debt Additional Information (Detail)	Jan. 22, 2016 USD ($)	Jan. 22, 2016 GBP (£)	Jan. 22, 2016 GBP (£)	Dec. 31, 2015 USD ($)	Dec. 11, 2015 USD ($)	Aug. 31, 2015 USD ($)
Debt Instrument [Line Items]
Maturity obligation, 2016				$ 6,700,000
Maturity obligation, 2017				26,700,000
Maturity obligation, 2018				26,700,000
Maturity obligation, 2019				26,700,000
Maturity obligation, 2020				353,100,000
Maturity obligation, thereafter				26,700,000
Amounts drawn on bank guarantees and letters of credit				0
Cash collateral				2,400,000
Standby Letters of Credit
Debt Instrument [Line Items]
Line of credit, maximum borrowing capacity				7,900,000
Senior Notes | Revolving Credit Facility
Debt Instrument [Line Items]
Line of credit, maximum borrowing capacity						$ 125,000,000.0
Senior Revolving Credit Facility Maturing in 2020 | Standby Letters of Credit
Debt Instrument [Line Items]
Line of credit, maximum borrowing capacity				3,500,000
Senior Revolving Credit Facility Maturing in 2020 | Senior Notes | Revolving Credit Facility
Debt Instrument [Line Items]
Line of credit, maximum borrowing capacity					$ 575,000,000.0
Unused senior revolving credit facility				$ 244,900,000
Subsequent Event | Multi-currency Notes Due in 2031 | Notes Payable
Debt Instrument [Line Items]
Notes payable, principal amount	$ 80,000,000		£ 54,900,000.0
Notes payable, annual repayment installments	$ 8,900,000	£ 6,100,000.0
Notes payable, interest rate	3.40%		3.40%
Minimum fixed charges coverage ratio (not less than)	1.50	1.50
Consolidated leverage ratio (not to exceed)	3.25	3.25