Supplemental Balance Sheet, Income Statement and Cash Flow Information - Accumulated Other Comp Inc (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Changes in accumulated other comprehensive income (loss)
Balance at the beginning of the period	$ 2,700,850
Adoption of ASU No. 2016-01	0
Other comprehensive income (loss), net of tax	17,537	$ (40,510)	$ 23,304
Balance at the end of the period	1,982,811	2,700,850
Accumulated Other Comprehensive Income
Changes in accumulated other comprehensive income (loss)
Balance at the beginning of the period	(29,325)	11,185
Other comprehensive income (loss) before reclassifications	16,943	(31,962)
Amounts reclassified from accumulated other comprehensive income (loss)	594	596
Other comprehensive income (loss), net of tax	17,537	(40,510)
Balance at the end of the period	(11,788)	(29,325)	11,185
Accumulated Net Gain (Loss) from Designated or Qualifying Cash Flow Hedge
Changes in accumulated other comprehensive income (loss)
Balance at the beginning of the period	(492)	(922)
Amounts reclassified from accumulated other comprehensive income (loss)	427	430
Other comprehensive income (loss), net of tax	427	430
Balance at the end of the period	(65)	(492)	(922)
Unrealized gains (losses) on available-for-sale securities
Changes in accumulated other comprehensive income (loss)
Balance at the beginning of the period		9,144
Other comprehensive income (loss), net of tax		(9,144)
Balance at the end of the period			9,144
Defined benefit pension plan items
Changes in accumulated other comprehensive income (loss)
Balance at the beginning of the period	(3,945)	(4,111)
Amounts reclassified from accumulated other comprehensive income (loss)	167	166
Other comprehensive income (loss), net of tax	167	166
Balance at the end of the period	(3,778)	(3,945)	(4,111)
Foreign currency items
Changes in accumulated other comprehensive income (loss)
Balance at the beginning of the period	(24,888)	7,074
Other comprehensive income (loss) before reclassifications	16,943	(31,962)
Other comprehensive income (loss), net of tax	16,943	(31,962)
Balance at the end of the period	$ (7,945)	(24,888)	$ 7,074
Accounting Standards Update 2016-01
Changes in accumulated other comprehensive income (loss)
Adoption of ASU No. 2016-01		9,144
Accounting Standards Update 2016-01 | Accumulated Other Comprehensive Income
Changes in accumulated other comprehensive income (loss)
Adoption of ASU No. 2016-01		(9,144)
Accounting Standards Update 2016-01 | Unrealized gains (losses) on available-for-sale securities
Changes in accumulated other comprehensive income (loss)
Adoption of ASU No. 2016-01		$ (9,144)