Income Taxes (Details) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Current
Federal	$ (54,312,000)	$ 49,236,000	$ 37,307,000
State	(3,906,000)	3,860,000	6,226,000
Foreign	(137,000)	(20,080,000)	20,889,000
Total current	(58,355,000)	33,016,000	64,422,000
Deferred
Federal	103,851,000	(45,330,000)	80,701,000
State	15,040,000	(1,747,000)	3,108,000
Foreign	(102,374,000)	(85,143,000)	(17,006,000)
Total deferred	16,518,000	(132,220,000)	66,803,000
Total
Federal	49,539,000	3,906,000	118,008,000
State	11,134,000	2,113,000	9,334,000
Foreign	(102,511,000)	(105,223,000)	3,883,000
Total	(41,838,000)	(99,204,000)	131,225,000
Foreign pretax earnings (losses)	222,300,000	(1,200,000,000)	84,000,000
Deferred income tax assets:
Net operating losses and credit carryforwards	278,016,000	156,387,000
Accrued expenses	5,167,000	14,827,000
Contingent interest	42,763,000	39,581,000
Other postretirement benefits	223,346,000	247,578,000
Pension obligations	2,925,000	23,725,000
Other	15,243,000	34,214,000
Total	567,460,000	516,312,000
Less: valuation allowance for deferred income tax assets	(166,265,000)	(20,919,000)
Net deferred income tax assets	401,195,000	495,393,000
Deferred income tax liabilities:
Prepaid expenses	(13,494,000)	(12,465,000)
British Columbia mineral tax	(184,680,000)	(243,229,000)
Property, plant and equipment	(990,580,000)	(943,523,000)
Total deferred income tax liabilities	(1,188,754,000)	(1,199,217,000)
Net deferred tax liability	(787,559,000)	(703,824,000)
Deferred income taxes are classified as follows:
Current deferred income tax asset	37,067,000	58,526,000
Noncurrent deferred income tax asset		160,422,000
Other current liabilities	(1,759,000)	(1,085,000)
Noncurrent deferred income tax liability	(822,867,000)	(921,687,000)
Net deferred tax liability	(787,559,000)	(703,824,000)
Unrecognized deferred income tax assets excluding interest and penalties	166,300,000
Increase in valuation allowances on unrealizable tax assets	145,322,000	19,189,000
Income tax expense (benefit) at the entity's effective tax rate differed from the statutory rate of 35%
Income (loss) from continuing operations before income tax expense	(400,841,000)	(1,164,759,000)	494,823,000
Tax expense (benefit) at statutory tax rate of 35%	(140,294,000)	(407,665,000)	173,188,000
Federal statutory income tax rate (as a percent)	35.00%	35.00%	35.00%
Excess depletion benefit	(17,524,000)	(26,107,000)	(32,370,000)
Taxation of foreign operations	(5,663,000)	(11,945,000)	(36,545,000)
British Columbia mineral tax foreign currency effect	(26,778,000)	3,643,000	(12,336,000)
British Columbia mineral tax	(14,697,000)	(22,365,000)	24,290,000
Goodwill impairment		372,543,000
State and local income tax, net of federal effect	(6,947,000)	2,470,000	7,394,000
U.S. domestic production activities benefit		(2,950,000)	(5,583,000)
Valuation allowance on deferred tax assets	145,322,000	19,189,000
Impact of statutory tax rate changes	14,660,000	(3,772,000)
Credits and other incentives	(659,000)	(2,301,000)
Impact of West Virginia legal entity restructuring	10,084,000
Acquisition costs			8,078,000
Other	658,000	(19,944,000)	5,109,000
Total	(41,838,000)	(99,204,000)	131,225,000
Federal
Income Taxes
NOLs	77,100,000
State
Income Taxes
NOLs	343,000,000
Non-U.S.
Income Taxes
NOLs	707,200,000
Canada
Income Taxes
Operating loss carryforwards subject to expiration between 2031 and 2032	581,900,000
Canadian unrealized losses incurred	13,800,000
U.K.
Income Taxes
Operating loss carryforwards with indefinite carryforward period	$ 125,300,000