Liabilities - Convertible Senior Notes - Interest Expense (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Non-Cash Interest Expense
Amortization of debt discount/transaction costs			$ 477	$ 7,100
Total Interest Expense	$ 2,706	$ 6,806	5,410	13,541
2023 Notes
Cash Interest Expense
Coupon interest expense	136	889	272	1,778
Non-Cash Interest Expense
Amortization of debt discount/transaction costs	$ 24	1,390	$ 48	2,754
Convertible Debt, Fair Value by Fair Value Hierarchy Level	Level 2		Level 2
Estimated fair value	$ 20,000		$ 20,000
2025 Notes
Cash Interest Expense
Coupon interest expense	1,159	1,159	2,318	2,319
Non-Cash Interest Expense
Amortization of debt discount/transaction costs	$ 114	1,185	$ 226	2,348
Convertible Debt, Fair Value by Fair Value Hierarchy Level	Level 2		Level 2
Estimated fair value	$ 148,000		$ 148,000
2027 Notes
Cash Interest Expense
Coupon interest expense	1,172	1,172	2,344	2,344
Non-Cash Interest Expense
Amortization of debt discount/transaction costs	$ 101	$ 1,011	$ 202	$ 1,998
Convertible Debt, Fair Value by Fair Value Hierarchy Level	Level 2		Level 2
Estimated fair value	$ 197,700		$ 197,700