Long-Term Debt - Additional Information (Detail)	0 Months Ended	6 Months Ended				6 Months Ended				6 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2014 USD ($)	Jun. 30, 2014 IKB Loan [Member] Installment	Apr. 11, 2013 IKB Loan [Member] USD ($)	Apr. 11, 2013 IKB Loan [Member] EUR (€)	Jun. 30, 2014 Maximum [Member]	Jun. 30, 2014 Federal Funds Rate [Member]	Jun. 30, 2014 5.375% Notes [Member]	Oct. 03, 2012 5.375% Notes [Member] USD ($)	Jun. 30, 2014 Revolving Credit Facility [Member]	Nov. 21, 2011 Revolving Credit Facility [Member] USD ($)	Jun. 30, 2014 Revolving Credit Facility, Due Nov. 2016 [Member]	Jun. 30, 2014 Revolving Credit Facility, Due Nov. 2016 [Member] Minimum [Member]	Jun. 30, 2014 Revolving Credit Facility, Due Nov. 2016 [Member] Maximum [Member]	Jun. 30, 2014 Revolving Credit Facility, Due Nov. 2016 [Member] Daily Euro Rate [Member] Minimum [Member]	Jun. 30, 2014 Revolving Credit Facility, Due Nov. 2016 [Member] Daily Euro Rate [Member] Maximum [Member]	Jun. 30, 2014 Letters of Credit [Member] USD ($)	Dec. 31, 2013 Letters of Credit [Member] USD ($)
Debt Instrument [Line Items]
Line of credit facility, maximum borrowing capacity											$ 350,000,000
Debt instrument maturity date								Oct. 15, 2020		Nov. 21, 2016		Nov. 30, 2016
Federal fund rate spread							0.50%						0.25%	1.25%	1.25%	2.25%
Margin over Euro-rate		1.00%
Leverage ratio	2.44					3.50
Aggregate principal amount				57,600,000	42,700,000				250,000,000
Percentage of aggregate principal amount of outstanding			2.05%					5.375%	5.375%
Net proceeds used to refinance previous debt		200,000,000
Frequency of interest payable								Semiannually
Debt instrument redemption								The 5.375% Notes are redeemable, in whole or in part, at anytime on or after October 15, 2016 at the redemption prices specified in the applicable Indenture. Prior to October 15, 2016, we may redeem some or all of the Notes at a "make-whole" premium as specified in the Indenture.
Number of installments			32
Installments beginning date			Jun. 30, 2015
Installments ending date			Mar. 31, 2023
Letters of credit issued																	5,200,000	5,200,000
Letters of credit outstanding																	$ 0