Financing arrangements (Details) | Jul. 20, 2015USD ($) | Dec. 31, 2015EUR (€) | Dec. 31, 2015USD ($) |
Line of Credit Facility [Line Items] | | | |
Interest rate | | 4.99% | 4.99% |
Line of Credit | Loans Payable | Interest rate swap | | | |
Line of Credit Facility [Line Items] | | | |
Fixed interest rate (in hundredths) | 6.20% | | |
Notes Payable | | | |
Line of Credit Facility [Line Items] | | | |
Long-term Debt, Gross | | € 26,000 | $ 28,000 |
Domestic Credit Facility | Line of Credit | | | |
Line of Credit Facility [Line Items] | | | |
Maximum borrowing capacity | | | 1,400,000 |
Domestic Credit Facility | Line of Credit | | | |
Line of Credit Facility [Line Items] | | | |
Maximum borrowing capacity | $ 20,300,000 | | |
Domestic Credit Facility | Line of Credit | Revolving Credit Facility | | | |
Line of Credit Facility [Line Items] | | | |
Maximum borrowing capacity | 15,000,000 | | |
Domestic Credit Facility | Line of Credit | Credit sub-facility standby letters of credit | | | |
Line of Credit Facility [Line Items] | | | |
Maximum borrowing capacity | 4,000,000 | | |
Domestic Credit Facility | Line of Credit | Loans Payable | | | |
Line of Credit Facility [Line Items] | | | |
Maximum borrowing capacity | $ 5,300,000 | | |
Term of loan | 3 years | | |
Commercial bank in Belgium | | | |
Line of Credit Facility [Line Items] | | | |
Maximum borrowing capacity | | 2,700,000 | 2,900,000 |
Commercial bank in Belgium | Line of Credit | | | |
Line of Credit Facility [Line Items] | | | |
Maximum borrowing capacity | | € 800,000 | $ 866,880 |
Interest rate (in hundredths) | | 9.75% | 9.75% |
Outstanding at the end of the period | | € 440,000 | $ 477,000 |
Commercial bank in Belgium | Outstanding performance guarantees | | | |
Line of Credit Facility [Line Items] | | | |
Maximum borrowing capacity | | 500,000 | 541,800 |
Outstanding at the end of the period | € | | 0 | |
Commercial bank in Belgium | Commercial Loan | | | |
Line of Credit Facility [Line Items] | | | |
Maximum borrowing capacity | | € 1,400,000 | $ 1,500,000 |
Prime Rate | Minimum | Commercial bank in Belgium | Line of Credit | | | |
Line of Credit Facility [Line Items] | | | |
Basis spread on variable rate | | 1.25% | |
Interest rate during period | | 2.91% | |
Prime Rate | Maximum | Commercial bank in Belgium | Line of Credit | | | |
Line of Credit Facility [Line Items] | | | |
Interest rate during period | | 3.98% | |
LIBOR | Line of Credit | Loans Payable | | | |
Line of Credit Facility [Line Items] | | | |
Basis spread on variable rate | 3.25% | | |
Base Rate | Line of Credit | Loans Payable | | | |
Line of Credit Facility [Line Items] | | | |
Basis spread on variable rate | 1.75% | | |
Tier One | LIBOR | Line of Credit | Revolving Credit Facility | | | |
Line of Credit Facility [Line Items] | | | |
Basis spread on variable rate | 2.25% | | |
Tier One | Base Rate | Line of Credit | Revolving Credit Facility | | | |
Line of Credit Facility [Line Items] | | | |
Basis spread on variable rate | 0.75% | | |
Tier Two | LIBOR | Line of Credit | Revolving Credit Facility | | | |
Line of Credit Facility [Line Items] | | | |
Basis spread on variable rate | 2.50% | | |
Tier Two | Base Rate | Line of Credit | Revolving Credit Facility | | | |
Line of Credit Facility [Line Items] | | | |
Basis spread on variable rate | 1.00% | | |
Tier Three | LIBOR | Line of Credit | Revolving Credit Facility | | | |
Line of Credit Facility [Line Items] | | | |
Basis spread on variable rate | 2.75% | | |
Tier Three | Base Rate | Line of Credit | Revolving Credit Facility | | | |
Line of Credit Facility [Line Items] | | | |
Basis spread on variable rate | 1.25% | | |