Long-Term Debt Additional Information (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended	9 Months Ended
	Sep. 30, 2020	Sep. 30, 2020	Oct. 29, 2020	Jun. 30, 2020	Dec. 31, 2019	Jun. 30, 2018	Nov. 14, 2017	Sep. 14, 2016
Debt Instrument
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Liabilities, Long-term Debt	$ 555,500	$ 555,500
Document Period End Date		Sep. 30, 2020
Line of Credit Facility, Initial Borrowing Base	2,100,000	$ 2,100,000
Revolving Credit Facility Elected Commitment Amount				$ 1,700,000
Debt Issuance Costs, Line of Credit Arrangements, Net	$ 9,400	$ 9,400			$ 8,900
Line of Credit Facility, Weighted Average Interest Rate	2.20%	2.20%
1.125% Convertible Senior Notes due 2021 [Member]
Debt Instrument
Debt Instrument, Interest Rate, Stated Percentage	1.125%	1.125%
Debt Instrument, Frequency of Periodic Payment		semi-annually
6.125% Senior Notes due 2024 [Member]
Debt Instrument
Debt Instrument, Interest Rate, Stated Percentage	6.125%	6.125%
Debt Instrument, Frequency of Periodic Payment		semi-annually
6.25% Senior Notes due 2025 [Member]
Debt Instrument
Debt Instrument, Interest Rate, Stated Percentage	6.25%	6.25%
Debt Instrument, Frequency of Periodic Payment		semi-annually
Senior Notes ($)	$ 102,300	$ 102,300
5.75% Senior Notes due 2026 [Member]
Debt Instrument
Debt Instrument, Interest Rate, Stated Percentage	5.75%	5.75%
Debt Instrument, Frequency of Periodic Payment		semi-annually
Senior Notes ($)	$ 750,000	$ 750,000
1.125% Convertible Senior Notes due 2021 [Member]
Debt Instrument
Convertible senior notes fair value	$ 200,000	$ 200,000			200,000
Convertible Note, Conversion Price	$ 85.39	$ 85.39
Liability component of gross proceeds of Convertible Notes	$ 160,500	$ 160,500
Debt Instrument, Convertible, Carrying Amount of Equity Component	39,500	39,500
Unamortized Debt Issuance Expense	(934)	(934)			(1,666)			$ (4,800)
Debt Instrument, Unamortized Discount	8,458	8,458			14,763
6.125% Senior Notes due 2024 [Member]
Debt Instrument
Unamortized Debt Issuance Expense	(3,876)	(3,876)			(4,611)			$ (7,800)
Senior Notes ($)	400,000	400,000			400,000
6.25% Senior Notes due 2025 [Member]
Debt Instrument
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Liabilities, Long-term Debt	555,500	$ 555,500
Debt Conversion, Original Debt, Interest Rate of Debt		101.00%
Debt Instrument, Repurchased Face Amount	447,700	$ 447,700
Redemption offer accepted		452,200
Debt Instrument, Repurchase Amount	6,200	6,200
Unamortized Debt Issuance Expense	(914)	(914)			0
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Noncurrent Liabilities, Long-term Debt	550,000	550,000
Senior Notes ($)	102,324	102,324			0
5.75% Senior Notes due 2026 [Member]
Debt Instrument
Unamortized Debt Issuance Expense	(6,873)	(6,873)			(5,734)		$ (7,600)
Senior Notes ($)	600,000	600,000			600,000
Debt Instrument, Unamortized Discount	1,490	$ 1,490			0
5.75% Senior Notes due 2026 [Member] | Issuance of additional aggregate principal for 2026 Senior Notes [Member]
Debt Instrument
Debt Conversion, Original Debt, Interest Rate of Debt		99.00%
Unamortized Debt Issuance Expense	(1,800)	$ (1,800)
Senior Notes ($)	150,000	150,000
Proceeds from Debt, Net of Issuance Costs	146,700
Debt Instrument, Unamortized Discount	1,500	1,500
Revolving Credit Facility
Debt Instrument
Long-term Line of Credit	$ 285,000	$ 285,000			$ 4,000
Initial Borrowing Base [Member] | Revolving Credit Facility
Debt Instrument
Line Of Credit Facility Initial Borrowing Capacity						$ 2,500,000
Alternate Base Rate Option [Member]
Debt Instrument
Line of Credit Facility, Interest Rate at Period End	0.75%	0.75%
LIBOR Option [Member]
Debt Instrument
Line of Credit Facility, Interest Rate at Period End	1.75%	1.75%
Unused Commitment Fee [Member]
Debt Instrument
Line of Credit Facility, Interest Rate at Period End	0.375%	0.375%
Subsequent Event [Member]
Debt Instrument
Line of Credit Facility, Initial Borrowing Base			$ 1,600,000
Revolving Credit Facility Elected Commitment Amount			$ 1,600,000