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Condensed Statements of Cash Flows (Details 4) - USD ($) $ in Thousands | 12 Months Ended
--- | ---
Dec. 31, 2015 | Dec. 31, 2014 | Dec. 31, 2013
Condensed Financial Statements, Captions [Line Items] |  |  |
Net cash provided by operating activities | $ 641,144 | $ 603,667 | $ 754,308
Capital expenditures | (625,375) | (608,028) | (531,332)
Net proceeds from sale or disposition of property and other | 54,569 | 29,598 | 40,802
Investments | 1,515 | (1,041) | 302
Net cash used in investing activities | (382,453) | (904,191) | (782,661)
Issuance of long-term debt | 345,920 | 606,084 | 507,924
Repayment of long-term debt | (569,498) | (368,249) | (423,707)
Proceeds from issuance of common stock | 21,898 | 150,060 | 14,554
Dividends paid | (142,835) | (136,712) | (98,405)
Excess tax benefit on stock-based compensation | 0 | 4,729 | 0
Tax withholding on stock-based compensation | 0 | (5,564) | 0
Net cash provided by financing activities | (255,730) | 325,194 | 36,866
Increase (decrease) in cash and cash equivalents | 2,736 | 24,515 | 8,298
Cash and cash equivalents - beginning of year | 81,855 | 57,340 | 49,042
Cash and cash equivalents - end of year | 84,591 | 81,855 | 57,340
MDU Resources Group, Inc. [Member] |  |  |
Condensed Financial Statements, Captions [Line Items] |  |  |
Net cash provided by operating activities | 255,273 | 208,208 | 188,259
Capital expenditures | (349,985) | (223,251) | (211,013)
Net proceeds from sale or disposition of property and other | 3,268 | 1,552 | 20,624
Investments in and advances to subsidiaries | (7,000) | (134,451) | (1,016)
Advances from subsidiaries | 100,000 | 64,500 | 10,000
Investments | 5 | (794) | 613
Net cash used in investing activities | (253,712) | (292,444) | (180,792)
Issuance of long-term debt | 224,185 | 148,959 | 77,924
Repayment of long-term debt | (108,008) | (76,432) | (85)
Proceeds from issuance of common stock | 21,898 | 150,060 | 14,554
Dividends paid | (142,835) | (136,712) | (98,405)
Excess tax benefit on stock-based compensation | 0 | 3,326 | 0
Tax withholding on stock-based compensation | 0 | (3,896) | 0
Net cash provided by financing activities | (4,760) | 85,305 | (6,012)
Increase (decrease) in cash and cash equivalents | (3,199) | 1,069 | 1,455
Cash and cash equivalents - beginning of year | 6,120 | 5,051 | 3,596
Cash and cash equivalents - end of year | $ 2,921 | $ 6,120 | $ 5,051

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