Summary of Significant Accounting Policies (Summary of Changes in Company's Allowance for Doubtful Accounts) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Allowance For Doubtful Accounts Receivable [Line Items]
Balance at Beginning of Period	$ 461	$ 338	$ 266
Provision	118	449	137
Write-offs	(398)	(326)	(65)
Balance at End of Period	$ 181	$ 461	$ 338