Valuation Account (Details) (Allowance for Doubtful Accounts Receivable [Member], USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2014		Dec. 31, 2013		Dec. 31, 2012
Allowance for Doubtful Accounts Receivable [Member]
Valuation Allowance [Line Items]
Balance at the beginning of the period			$ 67		$ 1,020
Charged to costs and expenses			(61)		17
Deductions for uncollectible accounts receivable written off, net of recoveries		[1]	(6)	[1]	(970)	[1]
Balance at the end of the period					$ 67

[1] Uncollectible accounts receivable written off, net of recoveries