Accounts Receivable (Allowance) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Allowance for doubtful accounts:
Balance, beginning of period	$ 193	$ 52	$ 268
Provisions for losses on accounts receivables, net of adjustments	0	141	(83)
Accounts receivable written off, net of recoveries	(22)	0	(133)
Balance, end of period	$ 171	$ 193	$ 52