Common Stock	3 Months Ended
Mar. 31, 2015
Equity [Abstract]
Common Stock	Note 5 – Common Stock On March 10, 2015, the Company filed with the Securities Exchange Commission (“SEC”) an automatic shelf registration statement on Form S-3 (File No. 333-202633), which became effective upon filing, for the offer and sale of up to $100,000,000 of the Company’s common stock from time to time in at-the-market offerings under the prospectus included therein and in accordance with the Sales Agency Agreement, dated March 10, 2015, between the Company and BNY Mellon Capital Markets, LLC (“BNYMCM”). During the quarter ending March 31, 2015, the Company sold, through the continuous equity offering program with BNYMCM as agent, an aggregate of 192,262 shares of the Company’s common stock in the open market at a weighted average price of $57.47 per share, resulting in proceeds to the Company of $10,938,956, net of $110,495 in agent commissions. As of March 31, 2015, the Company had up to $88,950,549 of common stock available for sale under the program. Net proceeds from the sale of shares of common stock under the Equity Shelf Program will be used for general corporate purposes, including the acquisition of property for the construction, completion, extension or improvement of pipeline systems and facilities located in and around the communities Southwest serves. In addition, during the three months ended March 31, 2015, the Company issued approximately 125,000 shares of common stock through the Stock Incentive Plan, Restricted Stock/Unit Plan, and Management Incentive Plan.

Common Stock

3 Months Ended

Mar. 31, 2015

Note 5 – Common Stock

On March 10, 2015, the Company filed with the Securities Exchange Commission (“SEC”) an automatic shelf registration statement on Form S-3 (File No. 333-202633), which became effective upon filing, for the offer and sale of up to $100,000,000 of the Company’s common stock from time to time in at-the-market offerings under the prospectus included therein and in accordance with the Sales Agency Agreement, dated March 10, 2015, between the Company and BNY Mellon Capital Markets, LLC (“BNYMCM”). During the quarter ending March 31, 2015, the Company sold, through the continuous equity offering program with BNYMCM as agent, an aggregate of 192,262 shares of the Company’s common stock in the open market at a weighted average price of $57.47 per share, resulting in proceeds to the Company of $10,938,956, net of $110,495 in agent commissions. As of March 31, 2015, the Company had up to $88,950,549 of common stock available for sale under the program. Net proceeds from the sale of shares of common stock under the Equity Shelf Program will be used for general corporate purposes, including the acquisition of property for the construction, completion, extension or improvement of pipeline systems and facilities located in and around the communities Southwest serves.

In addition, during the three months ended March 31, 2015, the Company issued approximately 125,000 shares of common stock through the Stock Incentive Plan, Restricted Stock/Unit Plan, and Management Incentive Plan.