Other Assets, Other Long-term Liabilities and Other Income (Expense), Net (Other Assets and Other Long-term Liabilities) (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Other Assets
Insurance claim receivable	$ 36,945	$ 34,839
Deferred income taxes	36,854	22,877
Deferred costs		7,711
Mineral reserves	3,199	3,199
Deposits	671	677
Other long-term assets	10,228	6,311
Other assets	87,897	75,614
Other Long-term Liabilities
Acquisition related liabilities	32,814	51,102
Insurance claim payable	36,897	34,774
Pension liability	32,403	19,831
Employee benefit related liabilities	2,476	2,536
Mineral royalties payable	1,727	1,727
Deferred lease incentive	462	1,143
Other	8,017	6,745
Other Long-term Liabilities	$ 114,796	$ 117,858