Valuation and Qualifying Accounts (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Other assets — other notes and accounts receivable
Reserves deducted from asset accounts:
Balance at Beginning of Year	$ 775	$ 1,043	$ 17
Additions (Reductions) Charged to Costs and Expenses	0	346	1,039
Charged to Other Accounts	0	0	0
Deductions	616	614	13
Balance at End of Year	159	775	1,043
Current assets — supplies and inventory
Reserves deducted from asset accounts:
Balance at Beginning of Year	8,446	12,589	13,107
Additions (Reductions) Charged to Costs and Expenses	580	503	1,961
Charged to Other Accounts	(76)	(2,274)	0
Deductions	2,325	2,372	2,479
Balance at End of Year		8,446	12,589
Deferred income taxes
Reserves deducted from asset accounts:
Balance at Beginning of Year	43,322	34,663	2,831
Additions (Reductions) Charged to Costs and Expenses		8,659	31,832
Charged to Other Accounts	0	0	0
Deductions	0	0	0
Balance at End of Year	$ 270,251	$ 43,322	$ 34,663

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Total of allowances and reserves, the valuation and qualifying accounts that are either netted against the cost of an asset (in order to value it at its carrying value) or that reflect a liability established to represent expected future costs.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 235

-SubTopic 10

-Section S99

-Paragraph 4

-URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e24092-122690

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 09

-Article 12

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