Collaborative And Other Arrangements Narrative (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Collaborative and Other Arrangements [Abstract]
Cash Outflows and Accrued Up-front Payments Related to Collaborative and Other Similar Arrangements	$ 206	$ 284	$ 393	$ 304
Up-front Collaboration and Licensing Expenses Related to Collaborative and Similar Arrangements	$ 165	$ 160	$ 291	$ 160