Related Party Transactions (Annual Maturities of Amounts Outstanding) (Details) - Majority Shareholder - Sumitomo Dainippon Pharma Co., Ltd. - Letter Agreement with Sumitomo Dainippon Pharma, Co., Ltd. - Term Loan $ in Thousands	Mar. 31, 2021 USD ($)
Related Party Transaction [Line Items]
2022	$ 0
2023	0
2024	0
2025	358,700
Total	$ 358,700

Related Party Transactions (Annual Maturities of Amounts Outstanding) (Details) - Majority Shareholder - Sumitomo Dainippon Pharma Co., Ltd. - Letter Agreement with Sumitomo Dainippon Pharma, Co., Ltd. - Term Loan
$ in Thousands

Mar. 31, 2021

USD ($)

2022

$ 0

358,700

$ 358,700

Amount, after unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

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