Significant Accounting Policies, Stock-Based Compensation Expense (Details) $ / shares in Units, $ in Thousands	3 Months Ended
Mar. 31, 2021 USD ($) Period $ / shares shares	Mar. 31, 2020 USD ($) shares
Stock-based Compensation Expense [Abstract]
Stock-based compensation expense	$ 37,861	$ 40,790
Cost of Sales [Member]
Stock-based Compensation Expense [Abstract]
Stock-based compensation expense	182	237
Research, Development and Patent Expense [Member]
Stock-based Compensation Expense [Abstract]
Stock-based compensation expense	25,899	25,556
Selling, General and Administrative Expense [Member]
Stock-based Compensation Expense [Abstract]
Stock-based compensation expense	11,780	$ 14,997
Stock Options [Member]
Unrecognized Compensation Expense [Abstract]
Unrecognized compensation expense related to non-vested stock options	$ 101,800
Weighted average period for recognition	1 year 4 months 24 days
Stock Options [Member] \| Board of Directors [Member]
Stock-based Compensation Expense [Abstract]
Stock options granted (in shares) \| shares	0	0
Stock Options [Member] \| Employees [Member]
Weighted-Average Assumptions [Abstract]
Risk-free interest rate	0.50%	1.60%
Dividend yield	0.00%	0.00%
Volatility	55.10%	58.90%
Expected life	4 years 10 months 24 days	4 years 8 months 12 days
ESPP [Member]
Weighted-Average Assumptions [Abstract]
Risk-free interest rate	0.10%	1.10%
Dividend yield	0.00%	0.00%
Volatility	39.10%	47.20%
Expected life	6 months	6 months
RSUs [Member]
Unrecognized Compensation Expense [Abstract]
Unrecognized compensation cost related to non-vested units	$ 109,600
Weighted average period for recognition	1 year 9 months 18 days
RSUs [Member] \| Board of Directors [Member]
Stock-based Compensation Expense [Abstract]
Units granted (in shares) \| shares	0	0
RSUs [Member] \| Board of Directors [Member] \| Maximum [Member]
RSUs and PRSUs [Abstract]
Vesting period	4 years
RSUs [Member] \| Board of Directors [Member] \| Minimum [Member]
RSUs and PRSUs [Abstract]
Vesting period	1 year
RSUs [Member] \| Employees [Member]
RSUs and PRSUs [Abstract]
Vesting period	4 years
Weighted-average grant date fair value (in dollars per share) \| $ / shares	$ 62.02
PRSUs [Member]
Unrecognized Compensation Expense [Abstract]
Unrecognized compensation cost related to non-vested units	$ 3,800
Weighted average period for recognition	1 year 8 months 12 days
PRSUs [Member] \| Chief Executive Officer, Dr. Brett Monia [Member]
RSUs and PRSUs [Abstract]
Number of performance periods \| Period	3
Vesting period	3 years
Number of units guaranteed to vest \| shares	0
Weighted-average grant date fair value (in dollars per share) \| $ / shares	$ 77.17
PRSUs [Member] \| Chief Executive Officer, Dr. Brett Monia [Member] \| Maximum [Member]
RSUs and PRSUs [Abstract]
Percentage of units guaranteed to vest	150.00%
PRSUs [Member] \| Chief Executive Officer, Dr. Brett Monia [Member] \| Minimum [Member]
RSUs and PRSUs [Abstract]
Percentage of units guaranteed to vest	0.00%
PRSUs [Member] \| Chief Executive Officer, Dr. Brett Monia [Member] \| One-Year Period [Member]
RSUs and PRSUs [Abstract]
Vesting percentage	33.30%
PRSUs [Member] \| Chief Executive Officer, Dr. Brett Monia [Member] \| Two-Year Period [Member]
RSUs and PRSUs [Abstract]
Vesting percentage	33.30%
PRSUs [Member] \| Chief Executive Officer, Dr. Brett Monia [Member] \| Three-Year Period [Member]
RSUs and PRSUs [Abstract]
Vesting percentage	33.30%

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Amount of cost to be recognized for nonvested award under share-based payment arrangement. Excludes share and unit options.

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The number of grants made during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan).

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The estimated dividend rate (a percentage of the share price) to be paid (expected dividends) to holders of the underlying shares over the option's term.

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Gross number of share options (or share units) granted during the period.

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A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

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