Commitments (Narrative) (Details) - USD ($)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Commitments and Contingencies Disclosure [Line Items]
Operating lease rental payments due in 2016	$ 83,272,000
Operating lease rental payments due in 2017	66,770,000
Operating lease rental payments due in 2018	56,393,000
Operating lease rental payments due in 2019	45,525,000
Operating lease rental payments due in 2020	46,761,000
Rental expenses for non-cancellable lease, including contingent payments	111,425,000	$ 144,981,000	$ 192,482,000
Commitments for capital expenditures	501,217,000
Malaysia [Member]
Commitments and Contingencies Disclosure [Line Items]
Commitments for capital expenditures	283,017,000
United States [Member]
Commitments and Contingencies Disclosure [Line Items]
Commitments for capital expenditures	30,661,000
Eagle Ford Shale [Member]
Commitments and Contingencies Disclosure [Line Items]
Commitments for capital expenditures	109,800,000
Namibia [Member]
Commitments and Contingencies Disclosure [Line Items]
Commitments for capital expenditures	45,179,000
Australia [Member]
Commitments and Contingencies Disclosure [Line Items]
Commitments for capital expenditures	15,376,000
Drilling Rigs And Associated Equipment [Member]
Commitments and Contingencies Disclosure [Line Items]
Commitments for capital expenditures	60,816,000
Processing Production Handling and Transportation Services [Member]
Commitments and Contingencies Disclosure [Line Items]
Operating lease rental payments due in 2016	30,307,000
Operating lease rental payments due in 2017	25,649,000
Operating lease rental payments due in 2018	17,542,000
Operating lease rental payments due in 2019	978,000
Operating lease rental payments due in 2020	1,003,000
Processing and transportation charges	32,473,000	34,597,000	40,254,000
El Dorado Promise Annual Commitment from 2007 to 2016 [Member]
Commitments and Contingencies Disclosure [Line Items]
Future commitments	5,000,000
Accretion costs	$ 172,000	$ 541,000	$ 805,000