Summary of Significant Accounting Policies (Receivables) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Allowance for Doubtful Accounts Receivable
Balance at beginning of year	$ 811	$ 531	$ 488
Provision and reserve adjustments	152	(305)	(78)
Write-offs less recoveries	(182)	(25)	(35)
Balance at end of year	$ 477	$ 811	$ 531