Significant Accounting Policies - Change in Accounting Policy - ASC Topic 606 (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Jan. 01, 2018
Accounting Changes
Net sales	$ 113,202	$ 108,954	$ 97,822	$ 99,371	$ 98,972	$ 126,757	$ 157,779	$ 158,574	$ 419,349	$ 542,082	$ 475,686
Cost of sales									261,155	348,363	299,458
Income tax expense (benefit)									777	(26,746)	(37,594)
Net income (loss)	$ (32,871)	$ (11,767)	$ (15,565)	$ (18,530)	$ (144,674)	$ (8,953)	$ (237,634)	$ (15,827)	$ (78,733)	$ (407,088)	$ (51,396)
Diluted earnings (loss) per share (in dollars per share)	$ (0.69)	$ (0.25)	$ (0.33)	$ (0.40)	$ (3.11)	$ (0.19)	$ (5.02)	$ (0.34)	$ (1.66)	$ (8.63)	$ (1.16)
ASU 2014-09, Revenue from Contracts with Customers
Accounting Changes
Change in Accounting Principle, Accounting Standards Update, Adopted												true
Change in Accounting Principle, Accounting Standards Update, Transition Option Elected												Retrospective