Long-Term Debt (Narrative) (Details) - Secured Term Loan Facility [Member] - USD ($) $ / shares in Units, $ in Thousands		1 Months Ended			3 Months Ended
	Mar. 10, 2021	Mar. 29, 2024	Mar. 29, 2023	Mar. 29, 2022	Mar. 31, 2021	Mar. 29, 2021
Debt Instrument [Line Items]
Aggregate principal amount	$ 80,000
Drew amount						$ 25,000
Net proceeds	$ 24,400
Interest rate description	Amounts drawn bear interest at a floating rate equal to the greater of either (i) 8.75% plus the prime rate as reported in The Wall Street Journal minus 3.25%, or (ii) 8.75% (such greater amount, the “Base Interest Rate”). Subject to there not having occurred any default or event of default under the loan agreement, the Base Interest Rate will be reduced by 25 basis points upon the occurrence of each of the first three of the four following events to occur:
Net Lenzilumab Product Revenue	$ 100,000
Interest rate	6.75%				9.00%
Unrestricted cash	$ 10,000
Unrestricted net cash proceeds	$ 100,000
Conversion price	$ 19.57
Interest expense					$ 18
Convertible Notes Payable [Member]
Debt Instrument [Line Items]
Aggregate principal amount	$ 250,000
Subsequent Event [Member]
Debt Instrument [Line Items]
Percentage of amount borrowed if repayment occurs		1.00%	1.50%	2.00%
Minimum [Member]
Debt Instrument [Line Items]
Net Lenzilumab Product Revenue	250,000
Converted principal amount	5,000
Maximum [Member]
Debt Instrument [Line Items]
Net Lenzilumab Product Revenue	350,000
Unrestricted cash	20,000
Converted principal amount	10,000
Second tranche [Member] | Minimum [Member]
Debt Instrument [Line Items]
Drew amount	25,000
Second tranche [Member] | Maximum [Member]
Debt Instrument [Line Items]
Drew amount	35,000
Third tranche [Member]
Debt Instrument [Line Items]
Drew amount	$ 20,000