Organization and Significant Accounting Policies, Revenue Recognition - Deferred Revenue (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Deferred Revenue [Abstract]
Revenue recognized	$ 105,300	$ 95,100
Current portion of deferred contract revenue	160,256	125,336
Long-term deferred contract revenue	$ 567,359	108,026
Total deferred revenue		233,362
As Previously Reported Under Topic 605 [Member] | Topic 606 [Member]
Deferred Revenue [Abstract]
Current portion of deferred contract revenue		106,465
Long-term deferred contract revenue		72,708
Total deferred revenue		179,173
Topic 606 Adjustment [Member] | Topic 606 [Member]
Deferred Revenue [Abstract]
Current portion of deferred contract revenue		18,871
Long-term deferred contract revenue		35,318
Total deferred revenue		54,189
Topic 606 Adjustment [Member] | Topic 606 [Member] | Biogen [Member]
Deferred Revenue [Abstract]
Total deferred revenue		24,200
Topic 606 Adjustment [Member] | Topic 606 [Member] | AstraZeneca [Member]
Deferred Revenue [Abstract]
Total deferred revenue		15,900
Topic 606 Adjustment [Member] | Topic 606 [Member] | Novartis [Member]
Deferred Revenue [Abstract]
Total deferred revenue		11,800
Topic 606 Adjustment [Member] | Topic 606 [Member] | Other Partners [Member]
Deferred Revenue [Abstract]
Total deferred revenue		$ 2,300