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Columns in Cash Flows statement 'Consolidated Statements of Cash Flows (USD $)' have maximum duration 365 days and at least 74 values. Shorter duration columns must have at least one fourth (18) as many values. Column '10/1/2014 - 12/31/2014' is shorter (91 days) and has only 5 values, so it is being removed. 'Monetary' elements on report '165 - Disclosure - Investment in Unconsolidated Affiliate - Additional Information (Detail)' had a mix of different decimal attribute values. Warning: The equity rendering routine was not applied to 193 - Statement - Stockholders' Equity - Additional Information (Detail). None of the elements feature the 'periodStartLabel' preferred label role. 'Monetary' elements on report '202 - Disclosure - Related Party Transactions - Additional Information (Detail)' had a mix of different decimal attribute values. 'Monetary' elements on report '210 - Disclosure - Commitments and Contingencies - Additional Information (Detail)' had a mix of different decimal attribute values. Process Flow-Through: 102 - Statement - Consolidated Balance Sheets Process Flow-Through: Removing column 'Dec. 31, 2012' Process Flow-Through: Removing column 'Dec. 31, 2011' Process Flow-Through: 103 - Statement - Consolidated Balance Sheets [Parenthetical] Process Flow-Through: 104 - Statement - Consolidated Statements of Comprehensive Income Process Flow-Through: Removing column '3 Months Ended Dec. 31, 2014' Process Flow-Through: Removing column '3 Months Ended Sep. 30, 2014' Process Flow-Through: Removing column '3 Months Ended Jun. 30, 2014' Process Flow-Through: Removing column '3 Months Ended Mar. 31, 2014' Process Flow-Through: Removing column '3 Months Ended Dec. 31, 2013' Process Flow-Through: Removing column '3 Months Ended Sep. 30, 2013' Process Flow-Through: Removing column '3 Months Ended Jun. 30, 2013' Process Flow-Through: Removing column '3 Months Ended Mar. 31, 2013' Process Flow-Through: 105 - Statement - Consolidated Statements of Comprehensive Income [Parenthetical] Process Flow-Through: 107 - Statement - Consolidated Statements of Cash Flows Process Flow-Through: 118 - Statement - Regulatory Assets and Liabilities Process Flow-Through: 130 - Statement - Segments of Operation Process Flow-Through: 147 - Statement - Stockholders' Equity (Tables) Process Flow-Through: 151 - Statement - Segments of Operation (Tables) Process Flow-Through: 153 - Statement - Summary of Business - Additional Information (Detail) Process Flow-Through: 154 - Statement - Significant Accounting Policies - Intangible Asset Amortization (Detail) Process Flow-Through: 158 - Statement - Discontinued Operations - Consolidated Statement of Comprehensive Income (Detail) Process Flow-Through: Removing column '3 Months Ended Dec. 31, 2014' Process Flow-Through: Removing column '3 Months Ended Sep. 30, 2014' Process Flow-Through: Removing column '3 Months Ended Jun. 30, 2014' Process Flow-Through: Removing column '3 Months Ended Mar. 31, 2014' Process Flow-Through: Removing column '3 Months Ended Dec. 31, 2013' Process Flow-Through: Removing column '3 Months Ended Sep. 30, 2013' Process Flow-Through: Removing column '3 Months Ended Jun. 30, 2013' Process Flow-Through: Removing column '3 Months Ended Mar. 31, 2013' Process Flow-Through: 162 - Statement - Goodwill - changes in carrying amount of goodwill (Detail) Process Flow-Through: Removing column '3 Months Ended Dec. 31, 2013' Process Flow-Through: Removing column '12 Months Ended Dec. 31, 2012' Process Flow-Through: 164 - Statement - Goodwill - Additional Information (Detail) Process Flow-Through: Removing column '12 Months Ended Dec. 31, 2013' Process Flow-Through: 175 - Statement - Regulatory Assets and Liabilities - Liability is Equal to Percent of Asset Cost (Detail) Process Flow-Through: 188 - Statement - Credit Facilities and Long-Term Debt - Schedule of Aggregate Future Maturities of Notes Payable (Detail) Process Flow-Through: 193 - Statement - Stockholders' Equity - Additional Information (Detail) Process Flow-Through: 196 - Statement - Income Taxes - Summary of Income Tax Expense from Continuing Operations (Detail) Process Flow-Through: 205 - Statement - Segments of Operation - Summary of Financial Information for Operating Segments (Detail) Process Flow-Through: Removing column '3 Months Ended Dec. 31, 2014' Process Flow-Through: Removing column '3 Months Ended Sep. 30, 2014' Process Flow-Through: Removing column '3 Months Ended Jun. 30, 2014' Process Flow-Through: Removing column '3 Months Ended Mar. 31, 2014' Process Flow-Through: Removing column '3 Months Ended Dec. 31, 2013' Process Flow-Through: Removing column '3 Months Ended Sep. 30, 2013' Process Flow-Through: Removing column '3 Months Ended Jun. 30, 2013' Process Flow-Through: Removing column '3 Months Ended Mar. 31, 2013' Process Flow-Through: 206 - Statement - Segments of Operation - Schedule of Company's Asset by Operating Segment (Detail) egas-20141231.xml egas-20141231.xsd egas-20141231_cal.xml egas-20141231_def.xml egas-20141231_lab.xml egas-20141231_pre.xml true true