Accrued Liabilities (Details) - Warranty obligations (USD $) In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Warranty obligations [Abstract]
Balance at beginning of year	$ 288	$ 281	$ 274
Provisions	66	72
Deductions	(59)	(65)
Balance at end of year	$ 288	$ 281	$ 274