Revenue Recognition (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2019	Dec. 31, 2018
Contract with Customer, Asset, Gross	$ 597,429	$ 597,429	$ 673,616
Contract with Customer, Liability, Current	6,448	6,448	$ 19,566
Contract with Customer, Liability, Revenue Recognized	8,100	16,100
Revenue, Remaining Performance Obligation, Amount	$ 19,600	$ 19,600
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period	2 years	2 years
Minimum
License Agreement, Term of Agreement		1 year
Long-Duration Contracts, Assumptions by Product and Guarantee, Discount Rate	3.00%	3.00%
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period	1 year	1 year
Maximum
License Agreement, Term of Agreement		7 years
Long-Duration Contracts, Assumptions by Product and Guarantee, Discount Rate	6.00%	6.00%
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period	3 years	3 years