Debt and Capital Lease Obligations - U.S. Credit Agreement - Additional Information (Details) - Regions Bank	9 Months Ended
	Sep. 30, 2015 USD ($)
Line Of Credit Facility [Line Items]
Credit facility maximum borrowing capacity	$ 75,000,000
Credit facility, interest rate description	Borrowings under the Credit Agreement accrue interest at a variable rate, plus an applicable margin.
Interest rate on outstanding borrowings	4.50%
Credit facility maturity period	5 years
Credit Agreement, fee paid	$ 600,000
Credit facility collateral pledge percentage	65.00%
Revolving Loan Facility
Line Of Credit Facility [Line Items]
Credit facility maximum borrowing capacity	$ 32,500,000
Credit facility due date	Aug. 05, 2020
Term Loan Facility
Line Of Credit Facility [Line Items]
Credit facility maximum borrowing capacity	$ 30,000,000
Credit facility due date	Aug. 05, 2020
Credit facility, percentage of amount borrowed due on maturity date	60.00%