Fair Value of Assets and Liabilities - Carrying Value and Estimated Fair Value of Financial Instruments (Details) - USD ($) $ in Thousands	Mar. 31, 2025	Dec. 31, 2024	Mar. 31, 2024
Assets:
Cash and cash equivalents	$ 64,822	$ 76,896	$ 126,497
Carrying Value
Assets:
Cash and cash equivalents	64,822	76,896
Restricted cash and investments	35,242	48,968
Liabilities:
Borrowings under exchange and senior credit facility	400,823	430,823
Fair Value
Assets:
Cash and cash equivalents	64,822	76,896
Restricted cash and investments	35,242	48,968
Liabilities:
Borrowings under exchange and senior credit facility	405,032	436,838
Level 1 | Fair Value
Assets:
Cash and cash equivalents	64,822	76,896
Restricted cash and investments	35,242	48,968
Level 2 | Fair Value
Liabilities:
Borrowings under exchange and senior credit facility	405,032	436,838
8.625% Senior Secured Notes Due 2029 | Carrying Value
Liabilities:
Senior notes, fair value	650,000	650,000
8.625% Senior Secured Notes Due 2029 | Fair Value
Liabilities:
Senior notes, fair value	683,956	687,239
8.625% Senior Secured Notes Due 2029 | Level 2 | Fair Value
Liabilities:
Senior notes, fair value	683,956	687,239
10.250% Senior Notes due 2031 | Carrying Value
Liabilities:
Senior notes, fair value	625,000	625,000
10.250% Senior Notes due 2031 | Fair Value
Liabilities:
Senior notes, fair value	680,819	682,281
10.250% Senior Notes due 2031 | Level 2 | Fair Value
Liabilities:
Senior notes, fair value	$ 680,819	682,281
6.50% Exchangeable Senior Notes due 2026 | Carrying Value
Liabilities:
Senior notes, fair value		100
6.50% Exchangeable Senior Notes due 2026 | Fair Value
Liabilities:
Senior notes, fair value		314
6.50% Exchangeable Senior Notes due 2026 | Level 2 | Fair Value
Liabilities:
Senior notes, fair value		$ 314