Income Taxes - Reconciliation of Effective Tax Rate to Statutory Rate (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Reconciliation Of Income Tax Rate [Line Items]
Net income (loss) before income taxes	$ 3,245	$ 97,683
Tax expense computed at statutory rate	681	20,513
Noncontrolling interest	(374)	(11,475)
Non-deductible general and administrative expenses	230	94
State return to accrual	286	0
Refundable tax credits	0	(505)
State income taxes, net of Federal benefit	1,285	1,208
Valuation allowance	(443)	(7,393)
State rate change	0	28
Total income tax expense	$ 1,665	$ 2,470
Effective tax rate	51.30%	2.50%
U.S.
Reconciliation Of Income Tax Rate [Line Items]
Net income (loss) before income taxes	$ 3,245	$ 97,683
Statutory rate	21.00%	21.00%
Tax expense computed at statutory rate	$ 681	$ 20,513
Noncontrolling interest	(374)	(11,475)
Non-deductible general and administrative expenses	230	94
State return to accrual	286	0
Refundable tax credits	0	(505)
State income taxes, net of Federal benefit	1,285	1,208
Valuation allowance	(443)	(7,393)
State rate change	0	28
Total income tax expense	$ 1,665	$ 2,470
Effective tax rate	51.30%	2.50%
Canada
Reconciliation Of Income Tax Rate [Line Items]
Net income (loss) before income taxes	$ 0	$ 0
Statutory rate	27.00%	27.00%
Tax expense computed at statutory rate	$ 0	$ 0
Noncontrolling interest	0	0
Non-deductible general and administrative expenses	0	0
State return to accrual	0	0
Refundable tax credits	0	0
State income taxes, net of Federal benefit	0	0
Valuation allowance	0	0
State rate change	0	0
Total income tax expense	$ 0	$ 0
Effective tax rate	0.00%	0.00%