Acquisitions, Litigation, and Other Charges - Components of Charges (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Acquisition, Litigation and Other Special Charges [Abstract]
Acquisition related costs	$ 15,014,000	$ 51,000	$ 16,455,000	$ 51,000
Litigation	467,000	0	1,377,000	0
Severance, equity award modifications and acceleration	2,641,000	(547,000)	6,934,000	2,053,000
Non-offering related equity issuance expenses	(164,000)	0	1,347,000	1,242,000
Non-recurring public company implementation costs	0	162,000	0	162,000
Terminated site operations costs	6,000	66,000	344,000	66,000
Total other	2,483,000	(319,000)	8,625,000	3,523,000
Total acquisition, litigation, and other	$ 17,964,000	$ (268,000)	$ 26,457,000	$ 3,574,000