Revenue Recognition (Deferred Revenue) (Details) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Revenue Recognition [Abstract]
Balance at beginning of period	$ 45,760,000	$ 26,157,000
Deferred Revenue, Additions from Acquisitions	0	0	7,944,000
New contracts sold	35,610,000	31,617,000	20,569,000
Balance at end of period	59,915,000	45,760,000	26,157,000
Deferred Revenue, Revenue Recognized	(21,455,000)	(12,014,000)	$ (2,356,000)
Deferred Revenue, Current	25,777,000	18,607,000
Deferred Revenue, Noncurrent	$ 34,138,000	$ 27,153,000