Income Taxes - Textual (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Income Tax [Line Items]
Non-deductible stock-based compensation	$ 3,354	$ 1,982	$ 24,357
Change to valuation allowance on items affecting taxable income	5,468	2,003	6,952
Effect of the difference in federal and statutory rates	1,906	2,222	(15)
Income taxes receivable	615	235
Taxes payable	7,019	5,368
Deferred tax liability accrued and other liabilities	263	47
Deferred tax assets other current assets	$ 14,380	6,722
Operating loss carryforwards expiration period	2016 through 2031
Indefinite loss carryforwards	$ 115,946
Valuation allowance, deferred tax asset, increase (decrease), amount	5,468	2,003	6,952
Pension and other postretirement benefit plans, tax	0	1,112	$ (1,112)
Unrecognized tax benefits	4,200	4
Unrecognized tax benefits, income tax penalties and interest accrued	1	$ 1,093
United States Federal [Member]
Income Tax [Line Items]
Operating loss carryforwards	41,187
United States
Income Tax [Line Items]
Indefinite loss carryforwards	35,723
Foreign Tax Authority
Income Tax [Line Items]
Operating loss carryforwards	71,111
Canadian [Member]
Income Tax [Line Items]
Indefinite loss carryforwards	80,223
State and Local Jurisdiction [Member]
Income Tax [Line Items]
Operating loss carryforwards	182,738
Canada Revenue Agency [Member]
Income Tax [Line Items]
Effect of the difference in federal and statutory rates	$ 1,906