Other Balance Sheet Items Other Balance Sheet Non-Current Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Other Liabilities Disclosure [Abstract]
Deferred Income Taxes and Other Liabilities, Noncurrent	$ 308,112	$ 281,621
Operating Lease, Liability	4,564	0
Other Liabilities, Noncurrent	$ 312,676	$ 281,621