Financial Instruments (Details 1) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Financial assets and liabilities measured on a recurring basis at fair value
Mutual fund assets	$ 14,093	$ 12,464
Derivative assets:
Foreign currency contracts	67	100
Total assets at fair value	14,160	12,564
Derivative liabilities:
Foreign currency contracts	2	52
Interest rate contracts	57	36
Total liabilities at fair value	59	88
Level 1 [Member]
Financial assets and liabilities measured on a recurring basis at fair value
Mutual fund assets	14,093	12,464
Derivative assets:
Foreign currency contracts
Total assets at fair value	14,093	12,464
Derivative liabilities:
Foreign currency contracts
Interest rate contracts
Total liabilities at fair value
Level 2 [Member]
Financial assets and liabilities measured on a recurring basis at fair value
Mutual fund assets
Derivative assets:
Foreign currency contracts	67	100
Total assets at fair value	67	100
Derivative liabilities:
Foreign currency contracts	2	52
Interest rate contracts	57	36
Total liabilities at fair value	59	88
Level 3 [Member]
Financial assets and liabilities measured on a recurring basis at fair value
Mutual fund assets
Derivative assets:
Total assets at fair value
Derivative liabilities:
Foreign currency contracts
Interest rate contracts
Total liabilities at fair value