Accounts Receivable and Accounts Payable and Accrued Expenses Accounts Payable and Accrued Expenses (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Accounts Payable and Accrued Liabilities, Current [Abstract]
Capital Expenditures Incurred but Not yet Paid - Instant	$ 97,355	$ 357,156
Accrued Revenue And Severance Tax Payable	44,387	63,779
Accrued Lease Operating Expense	21,943	34,822
Accrual for Taxes Other than Income Taxes, Current	14,078	15,059
Employee-related Liabilities, Current	41,154	56,279
Interest Payable, Current	34,378	40,786
Other Accrued Liabilities, Current	49,222	72,803
Accounts payable and accrued expenses	$ 302,517	$ 640,684