| Accounts Receivable |
ACCOUNTS RECEIVABLE
Following is a summary of Accounts receivable, net included in the accompanying Condensed Consolidated Balance Sheets (in thousands) as of: | | | | | | | | | | | | | | | Accounts | Unbilled | Less Allowance for | Accounts | September 30, 2017 | Receivable, Trade | Revenue | Doubtful Accounts | Receivable, net | Electric Utilities | $ | 42,716 |
| $ | 29,762 |
| $ | (494 | ) | $ | 71,984 |
| Gas Utilities | 49,842 |
| 24,516 |
| (1,190 | ) | 73,168 |
| Power Generation | 1,010 |
| — |
| — |
| 1,010 |
| Mining | 3,534 |
| — |
| — |
| 3,534 |
| Oil and Gas | 3,590 |
| — |
| (83 | ) | 3,507 |
| Corporate | 629 |
| — |
| — |
| 629 |
| Total | $ | 101,321 |
| $ | 54,278 |
| $ | (1,767 | ) | $ | 153,832 |
|
| | | | | | | | | | | | | | | Accounts | Unbilled | Less Allowance for | Accounts | December 31, 2016 | Receivable, Trade | Revenue | Doubtful Accounts | Receivable, net | Electric Utilities | $ | 41,730 |
| $ | 36,463 |
| $ | (353 | ) | $ | 77,840 |
| Gas Utilities | 88,168 |
| 88,329 |
| (2,026 | ) | 174,471 |
| Power Generation | 1,420 |
| — |
| — |
| 1,420 |
| Mining | 3,352 |
| — |
| — |
| 3,352 |
| Oil and Gas | 3,991 |
| — |
| (13 | ) | 3,978 |
| Corporate | 2,228 |
| — |
| — |
| 2,228 |
| Total | $ | 140,889 |
| $ | 124,792 |
| $ | (2,392 | ) | $ | 263,289 |
|
| | | | | | | | | | | | | | | Accounts | Unbilled | Less Allowance for | Accounts | September 30, 2016 | Receivable, Trade | Revenue | Doubtful Accounts | Receivable, net | Electric Utilities | $ | 44,747 |
| $ | 30,970 |
| $ | (580 | ) | $ | 75,137 |
| Gas Utilities | 48,057 |
| 23,582 |
| (1,923 | ) | 69,716 |
| Power Generation | 1,165 |
| — |
| — |
| 1,165 |
| Mining | 3,612 |
| — |
| — |
| 3,612 |
| Oil and Gas | 3,341 |
| — |
| (13 | ) | 3,328 |
| Corporate | 1,659 |
| — |
| — |
| 1,659 |
| Total | $ | 102,581 |
| $ | 54,552 |
| $ | (2,516 | ) | $ | 154,617 |
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