Income Taxes - Carryforwards (Details) $ in Thousands	Dec. 31, 2017 USD ($)
Details of net operating loss carryforwards
Net operating loss	$ 236,144
2018 - 2022
Details of net operating loss carryforwards
Net operating loss	13,700
2023 - 2027
Details of net operating loss carryforwards
Net operating loss	12,669
2028 - 2037
Details of net operating loss carryforwards
Net operating loss	127,163
Indefinite
Details of net operating loss carryforwards
Net operating loss	82,612
Federal
Details of net operating loss carryforwards
Net operating loss	72,700
State
Details of net operating loss carryforwards
Net operating loss	77,800
Foreign | Indefinite
Details of net operating loss carryforwards
Net operating loss	$ 85,600