Additional Cash Flow Information - Supplemental Cash Flow Information Related to Leases (Details) - USD ($) $ in Thousands		1 Months Ended	9 Months Ended
	Jul. 16, 2019	Jul. 31, 2019	Sep. 30, 2019
Cash paid for amounts included in the measurement of lease liabilities:
Operating cash flows from operating leases			$ 8,062
Operating cash flows from finance leases			37,667
Financing cash flows from finance leases			28,879
Right-of-use assets obtained in exchange for lease obligations
Operating leases			6,077
Finance leases			$ 0
Exonics Therapeutics
Right-of-use assets obtained in exchange for lease obligations
Operating leases		$ 5,400
Payments to acquire businesses	$ 245,000