Accounts Receivable and Accounts Payable and Accrued Expenses Accounts Payable and Accrued Expenses (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Accounts Payable and Accrued Liabilities, Current [Abstract]
Capital Expenditures Incurred but Not yet Paid - Instant	$ 107,009	$ 97,355
Accrued Revenue And Severance Tax Payable	39,617	44,387
Accrued Lease Operating Expense	15,956	21,943
Accrual for Taxes Other than Income Taxes, Current	6,606	14,078
Employee-related Liabilities, Current	34,761	41,154
Derivative Settlement Payable	6,473	0
Interest Payable, Current	45,059	34,378
Other Accrued Liabilities, Current	44,227	49,222
Accounts payable and accrued expenses	$ 299,708	$ 302,517