Fair Value Measurements (Narrative) (Details) (USD $)	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Dec. 31, 2012	Dec. 31, 2011
Fair Value Measurements [Abstract]
Fair value of contingent consideration	$ 2,150		$ 2,150			$ 3,000
Adjusted gross profit under APA			5,428		6,752
Non-cash gain on change in fair value of contingent obligation included in general and administrative expense	$ 661,000	$ 0	$ 1,250,000