Accounts Receivable (Allowance) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Allowance for Doubtful Accounts Receivable [Roll Forward]
Balance, beginning of period	$ 321	$ 261	$ 52	$ 268
Provisions for losses on accounts receivables	(167)	(6)	102	(1)
Accounts receivable written off, net of recoveries	0	(13)	0	(25)
Balance, end of period	$ 154	$ 242	$ 154	$ 242