Revenue Recognition (Deferred Revenue) (Details) - USD ($)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Revenue Recognition [Abstract]
Balance at beginning of period	$ 59,915,000	$ 45,760,000	$ 26,157,000
New contracts sold	49,565,000	35,610,000	31,617,000
Balance at end of period	81,555,000	59,915,000	45,760,000
Deferred Revenue, Revenue Recognized	(27,925,000)	(21,455,000)	$ (12,014,000)
Deferred Revenue, Current	34,254,000	25,777,000
Deferred Revenue, Noncurrent	$ 47,301,000	$ 34,138,000