Summary of Significant Accounting Policies (Allowance for Doubtful Accounts) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Allowance for Doubtful Accounts Receivable [Roll Forward]
Balance at beginning of year	$ 890	$ 454	$ 321
Provision	412	829	725
Acquisitions	0	400	295
Writeoffs, net of recoveries	(721)	(793)	(887)
Balance at end of year	$ 581	$ 890	$ 454