Income Taxes - Income tax reconciliation (Details) - USD ($)	3 Months Ended								12 Months Ended
	Dec. 31, 2021	Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2021	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Income Taxes
Statutory tax rate									21.00%		35.00%
Reconciliation of effective income tax amount
Tax at statutory rate									$ (27,454,000)	$ (34,639,000)	$ (105,310,000)
State income taxes									(1,626,000)	(5,234,000)	(7,666,000)
Foreign income taxes									1,567,000	(516,000)	4,390,000
Nondeductible goodwill impairment											61,699,000
Cancellation of debt income									(6,429,000)
Permanent differences									359,000	218,000	1,275,000
Litigation settlement									2,000	71,000	3,310,000
Changes in valuation allowance									11,857,000	53,115,000	30,064,000
Unremitted earnings									1,072,000	(275,000)	1,604,000
GILTI Inclusion										(4,996,000)	3,772,000
Expiration of tax attributes									31,014,000	4,944,000	10,807,000
Other									1,294,000	896,000	3,697,000
Income tax expense	$ 8,226,000	$ 1,441,000	$ 2,007,000	$ (18,000)	$ 10,144,000	$ 320,000	$ 661,000	$ 2,459,000	11,656,000	13,584,000	$ 7,642,000
Income tax expense (benefit) GILTI									0
Estimated income tax expense (benefit) GILT										5,000,000.0
Income tax expense (benefit) BEAT									$ 0	$ 0