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-Publisher FASB
-Name Accounting Standards Codification
-Topic 260
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (c)
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-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
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Earnings Per Share (Anti-dilutive Shares) (Details) shares in Thousands	12 Months Ended
	Dec. 31, 2018 trading_day shares	Dec. 31, 2017 shares	Dec. 31, 2016 shares	Sep. 30, 2017
Joint venture shares
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive shares	0	255	0
3.00% convertible senior unsecured notes
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive shares	0	0	14,764
Stated interest rate (percent)	3.00%
Series J convertible perpetual preferred stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive shares	15,704	15,635	15,635
1.50% convertible senior unsecured notes
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive shares	0	0	9,868
Stated interest rate (percent)	1.50%
Unvested Time Based Units
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive shares		6	16
Market-based Units
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive shares		17	125
3.125% senior convertible notes
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Stated interest rate (percent)	3.125%			3.125%
Threshold consecutive trading days \| trading_day	40