Fair Value Measurements (Narrative) (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended		12 Months Ended
	Jun. 30, 2020	Jun. 30, 2020	Jun. 30, 2019	Dec. 31, 2019	Dec. 31, 2018
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Contingent earn-out	$ 0	$ 0		$ 557
Payments related to contingent consideration		0	$ 487
Recurring | Convertible senior note
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Convertible senior note net	192,000	192,000
Conversable, Inc. and AdvntageTec
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Contingent earn-out					$ 2,400
Conversable, Inc.
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Re-measurement to fair value increase (decrease)				500
AdvantageTec
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Re-measurement to fair value increase (decrease)	$ 300			200
Payments related to contingent consideration				500
Contingent earn-out
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Contingent earn-out increase (decrease)		(600)		(1,800)
Equity issued as payment for contingent consideration		300		1,000
Payment related to contingent consideration		294		1,487
Contingent earn-out | Conversable, Inc.
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Re-measurement to fair value increase (decrease)		0		(496)
Payments related to contingent consideration				500
Contingent earn-out | AdvantageTec
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Re-measurement to fair value increase (decrease)		$ (263)		$ 168