Long-Term Debt - Additional Information (Detail)	12 Months Ended						1 Months Ended			12 Months Ended				12 Months Ended		0 Months Ended	1 Months Ended		12 Months Ended		12 Months Ended
	Dec. 31, 2014 USD ($)	Dec. 31, 2013 USD ($)	Dec. 31, 2012 USD ($)	Dec. 31, 2014 EUR (€)	Dec. 31, 2013 EUR (€)	Jan. 15, 2015 Subsequent Event [Member] USD ($)	Sep. 30, 2012 Revolving Credit Facility [Member] USD ($)	Jun. 30, 2012 Revolving Credit Facility [Member] USD ($)	May 31, 2012 Revolving Credit Facility [Member] USD ($)	Dec. 31, 2014 Revolving Credit Facility [Member]	Dec. 31, 2013 Revolving Credit Facility [Member] USD ($)	Dec. 31, 2012 Revolving Credit Facility [Member] USD ($)	Aug. 30, 2010 Revolving Credit Facility [Member] USD ($)	Dec. 31, 2013 Revolving Credit Facility [Member] LIBOR [Member]	Dec. 31, 2012 Revolving Credit Facility [Member] LIBOR [Member]	Aug. 30, 2010 Term Loan Facility [Member] USD ($)	May 31, 2012 Term Loan Facility [Member] USD ($)	May 31, 2011 Term Loan Facility [Member] USD ($)	Dec. 31, 2014 Term Loan Facility [Member] USD ($)	Dec. 31, 2013 Term Loan Facility [Member] USD ($)	Dec. 31, 2014 Term Loan Facility [Member] Maximum [Member] Base rate [Member]	Dec. 31, 2014 New Credit Agreement [Member] Maximum [Member] LIBOR [Member]	Dec. 31, 2014 New Credit Agreement [Member] Maximum [Member] Base rate [Member]	Dec. 31, 2014 Prior Credit Agreement [Member] LIBOR [Member]	Dec. 31, 2013 Prior Credit Agreement [Member] LIBOR [Member]
Debt Instrument [Line Items]
Debt instrument term (in years)										5 years									5 years
Maximum borrowing capacity	$ 7,000,000	$ 8,000,000		€ 5,800,000	€ 5,800,000								$ 200,000,000
Maximum borrowing capacity																100,000,000
Available capacity under the revolving credit facility						100,000,000
Repayment of debt obligation	20,000,000	16,000	188,695,000														87,500,000
Repayment of debt obligation							20,000,000	20,000,000	57,500,000
Amount outstanding	0										20,000,000	20,000,000
Margin on variable rate														2.50%	2.50%							3.25%	2.25%
Variable rate basis																					LIBOR
Effective interest rate (as a Percent)																								2.70%	2.70%
Contractual maturities of long-term debt	0
Revolving credit facility due date										Aug. 30, 2015
Amount of restricted net assets	181,800,000	168,500,000
Restricted cash	34,424,000	23,761,000
Debt issuance costs incurred																		800,000	5,000,000
Write-off of debt issue costs																	800,000
Deferred debt issuance costs, net																			$ 400,000	$ 1,100,000