Segment Information, Long Lived Assets by Major Market (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Long-Lived Assets by Major Market [Abstract]
Long-lived assets	$ 632,670	$ 597,930	$ 464,535
Major Market [Member] | United States [Member]
Long-Lived Assets by Major Market [Abstract]
Long-lived assets	348,028	354,410	317,516
Major Market [Member] | Mainland China [Member]
Long-Lived Assets by Major Market [Abstract]
Long-lived assets	152,312	136,845	89,447
Major Market [Member] | South Korea [Member]
Long-Lived Assets by Major Market [Abstract]
Long-lived assets	39,104	35,286	36,325
Major Market [Member] | Japan [Member]
Long-Lived Assets by Major Market [Abstract]
Long-lived assets	31,085	12,015	6,864
Major Market [Member] | All Others [Member]
Long-Lived Assets by Major Market [Abstract]
Long-lived assets	$ 62,141	$ 59,374	$ 14,383