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Quarterly Financial Data (Unaudited) (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands | 3 Months Ended | 12 Months Ended
--- | --- | ---
Dec. 31, 2017 | Sep. 30, 2017 | Jun. 30, 2017 | Mar. 31, 2017 | Dec. 31, 2016 | Sep. 30, 2016 | Jun. 30, 2016 | Mar. 31, 2016 | Dec. 31, 2017 | Dec. 31, 2016 | Dec. 31, 2015
Unaudited Quarterly Financial Data [Line Items] |  |  |  |  |  |  |  |  |  |  |
Total revenues |  |  |  |  |  |  |  |  | $ 2,471,406 | $ 2,425,800 | $ 2,744,965
Operating income |  |  |  |  |  |  |  |  | 847,471 | 856,086 | 1,009,238
Income (loss) from continuing operations |  |  |  |  |  |  |  |  | 628,381 | 4,479,586 | 907,621
Discontinued operations, net |  |  |  |  |  |  |  |  | 0 | 518 | 397
Net income |  |  |  |  |  |  |  |  | 628,381 | 4,480,104 | 908,018
Net income available to Common Shares |  |  |  |  |  |  |  |  | $ 600,363 | $ 4,289,072 | $ 863,277
Earnings per share – basic: |  |  |  |  |  |  |  |  |  |  |
Net income available to Common Shares |  |  |  |  |  |  |  |  | $ 1.64 | $ 11.75 | $ 2.37
Weighted average Common Shares outstanding |  |  |  |  |  |  |  |  | 366,968 | 365,002 | 363,498
Earnings per share – diluted: |  |  |  |  |  |  |  |  |  |  |
Net income available to Common Shares |  |  |  |  |  |  |  |  | $ 1.63 | $ 11.68 | $ 2.36
Weighted average Common Shares outstanding |  |  |  |  |  |  |  |  | 382,678 | 381,992 | 380,620
ERPOP [Member] |  |  |  |  |  |  |  |  |  |  |
Unaudited Quarterly Financial Data [Line Items] |  |  |  |  |  |  |  |  |  |  |
Total revenues |  |  |  |  |  |  |  |  | $ 2,471,406 | $ 2,425,800 | $ 2,744,965
Operating income |  |  |  |  |  |  |  |  | 847,471 | 856,086 | 1,009,238
Income (loss) from continuing operations |  |  |  |  |  |  |  |  | 628,381 | 4,479,586 | 907,621
Discontinued operations, net |  |  |  |  |  |  |  |  | 0 | 518 | 397
Net income |  |  |  |  |  |  |  |  | 628,381 | 4,480,104 | 908,018
Net income available to Units |  |  |  |  |  |  |  |  | $ 622,967 | $ 4,460,583 | $ 897,518
Earnings per share – basic: |  |  |  |  |  |  |  |  |  |  |
Net income available to Common Shares |  |  |  |  |  |  |  |  | $ 1.64 | $ 11.75 | $ 2.37
Weighted average Units outstanding |  |  |  |  |  |  |  |  | 379,869 | 378,829 | 377,074
Earnings per share – diluted: |  |  |  |  |  |  |  |  |  |  |
Net income available to Common Shares |  |  |  |  |  |  |  |  | $ 1.63 | $ 11.68 | $ 2.36
Weighted average Common Shares outstanding |  |  |  |  |  |  |  |  | 382,678 | 381,992 | 380,620
Scenario, Previously Reported [Member] |  |  |  |  |  |  |  |  |  |  |
Unaudited Quarterly Financial Data [Line Items] |  |  |  |  |  |  |  |  |  |  |
Total revenues | $ 630,704 | $ 624,122 | $ 612,480 | $ 604,100 | $ 605,489 | $ 606,074 | $ 595,154 | $ 619,083 |  |  |
Operating income | 214,764 | 217,786 | 210,550 | 204,371 | 224,070 | 209,373 | 206,018 | 216,625 |  |  |
Income (loss) from continuing operations | 130,084 | 144,196 | 204,160 | 149,941 | 301,987 | 217,246 | 228,365 | 3,731,988 |  |  |
Discontinued operations, net |  |  |  |  | 394 | 246 | 35 | (157) |  |  |
Net income | 130,084 | 144,196 | 204,160 | 149,941 | 302,381 | 217,492 | 228,400 | 3,731,831 |  |  |
Net income available to Common Shares | $ 124,669 | $ 137,457 | $ 195,268 | $ 142,969 | $ 276,477 | $ 207,543 | $ 218,067 | $ 3,586,985 |  |  |
Earnings per share – basic: |  |  |  |  |  |  |  |  |  |  |
Net income available to Common Shares | $ 0.34 | $ 0.37 | $ 0.53 | $ 0.39 | $ 0.76 | $ 0.57 | $ 0.60 | $ 9.84 |  |  |
Weighted average Common Shares outstanding | 367,442 | 366,996 | 366,820 | 366,605 | 365,256 | 365,109 | 365,047 | 364,592 |  |  |
Earnings per share – diluted: |  |  |  |  |  |  |  |  |  |  |
Net income available to Common Shares | $ 0.34 | $ 0.37 | $ 0.53 | $ 0.39 | $ 0.75 | $ 0.56 | $ 0.59 | $ 9.76 |  |  |
Weighted average Common Shares outstanding | 383,105 | 382,945 | 382,692 | 382,280 | 381,860 | 382,373 | 382,065 | 382,243 |  |  |
Scenario, Previously Reported [Member] | ERPOP [Member] |  |  |  |  |  |  |  |  |  |  |
Unaudited Quarterly Financial Data [Line Items] |  |  |  |  |  |  |  |  |  |  |
Total revenues | $ 630,704 | $ 624,122 | $ 612,480 | $ 604,100 | $ 605,489 | $ 606,074 | $ 595,154 | $ 619,083 |  |  |
Operating income | 214,764 | 217,786 | 210,550 | 204,371 | 224,070 | 209,373 | 206,018 | 216,625 |  |  |
Income (loss) from continuing operations | 130,084 | 144,196 | 204,160 | 149,941 | 301,987 | 217,246 | 228,365 | 3,731,988 |  |  |
Discontinued operations, net |  |  |  |  | 394 | 246 | 35 | (157) |  |  |
Net income | 130,084 | 144,196 | 204,160 | 149,941 | 302,381 | 217,492 | 228,400 | 3,731,831 |  |  |
Net income available to Units | $ 129,342 | $ 142,623 | $ 202,622 | $ 148,380 | $ 287,546 | $ 215,896 | $ 226,847 | $ 3,730,294 |  |  |
Earnings per share – basic: |  |  |  |  |  |  |  |  |  |  |
Net income available to Common Shares | $ 0.34 | $ 0.37 | $ 0.53 | $ 0.39 | $ 0.76 | $ 0.57 | $ 0.60 | $ 9.84 |  |  |
Weighted average Units outstanding | 380,325 | 379,906 | 379,733 | 379,504 | 379,081 | 379,008 | 378,934 | 378,289 |  |  |
Earnings per share – diluted: |  |  |  |  |  |  |  |  |  |  |
Net income available to Common Shares | $ 0.34 | $ 0.37 | $ 0.53 | $ 0.39 | $ 0.75 | $ 0.56 | $ 0.59 | $ 9.76 |  |  |
Weighted average Units outstanding | 383,105 | 382,945 | 382,692 | 382,280 | 381,860 | 382,373 | 382,065 | 382,243 |  |  |

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