Short-Term Debt (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011
Debt Disclosure [Abstract]
Short-term debt	$ 5,267	$ 8,987
Interest rate, minimum	1.90%	1.90%
Interest rate, maximum	2.90%	2.90%
Interest rate, weighted average	2.70%	2.70%