Income Taxes - Textual (Details) - USD ($)	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Income Tax [Line Items]
Effective Income Tax Rate Reconciliation, Nondeductible Expense, Other, Amount	$ 1,848,000	$ 163,000	$ 3,075,000
Non-deductible stock-based compensation	1,123,000	665,000	1,982,000
Change to valuation allowance on items affecting taxable income	6,605,000	3,565,000	(643,000)
Effect of the difference in federal and statutory rates	(4,579,000)	1,906,000	2,222,000
Income taxes receivable	1,506,000	615,000
Taxes payable	$ 4,547,000	7,019,000
Operating loss carryforwards expiration period	2016 through 2031
Indefinite loss carryforwards	$ 118,413,000
Valuation allowance, deferred tax asset, increase (decrease), amount	6,605,000	3,565,000	(643,000)
Pension and other postretirement benefit plans, tax	0	0	$ 1,112,000
Unrecognized tax benefits	1,543,000	4,000
Unrecognized tax benefits, income tax penalties and interest accrued	0	$ 595,000
United States Federal [Member]
Income Tax [Line Items]
Operating loss carryforwards	21,339,000
United States
Income Tax [Line Items]
Indefinite loss carryforwards	35,723,000
Foreign Tax Authority
Income Tax [Line Items]
Operating loss carryforwards	70,517,000
Canada
Income Tax [Line Items]
Indefinite loss carryforwards	82,691,000
State and Local Jurisdiction [Member]
Income Tax [Line Items]
Operating loss carryforwards	188,367,000
Canada Revenue Agency [Member]
Income Tax [Line Items]
Effect of the difference in federal and statutory rates	$ (4,579,000)