Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Balance at beginning of period	$ 2,583,070	$ 2,116,928	$ 2,353,959	$ 1,990,239
Other comprehensive income (loss) before reclassifications			(11,485)	4,135
Amounts reclassified from accumulated other comprehensive income (loss)			151	59
Total other comprehensive income (loss)	(177)	4,037	(11,334)	4,194
Balance at end of period	2,759,679	2,222,737	2,759,679	2,222,737
Unrealized Gains (Losses) on Available-for-Sale Debt Investments
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Balance at beginning of period			21	0
Other comprehensive income (loss) before reclassifications			(221)	168
Amounts reclassified from accumulated other comprehensive income (loss)			74	25
Total other comprehensive income (loss)			(147)	193
Balance at end of period	(126)	193	(126)	193
Defined Benefit Pension
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Balance at beginning of period			(4,218)	(4,820)
Other comprehensive income (loss) before reclassifications			0	0
Amounts reclassified from accumulated other comprehensive income (loss)			77	34
Total other comprehensive income (loss)			77	34
Balance at end of period	(4,141)	(4,786)	(4,141)	(4,786)
Foreign Currency Translation
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Balance at beginning of period			31,467	23,935
Other comprehensive income (loss) before reclassifications			(11,264)	3,967
Amounts reclassified from accumulated other comprehensive income (loss)			0	0
Total other comprehensive income (loss)			(11,264)	3,967
Balance at end of period	20,203	27,902	20,203	27,902
Total
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Balance at beginning of period	16,113	19,272	27,270	19,115
Total other comprehensive income (loss)	(177)	4,037	(11,334)	4,194
Balance at end of period	$ 15,936	$ 23,309	$ 15,936	$ 23,309