2.2.0.25falsefalse006090 - Disclosure - POSTRETIREMENT BENEFITStruefalsefalse1falsefalseUSDfalsefalse1/1/2011 - 3/31/2011 USD ($) USD ($) / shares $c00012http://www.sec.gov/CIK0000072020duration2011-01-01T00:00:002011-03-31T00:00:00u000Standardhttp://www.xbrl.org/2003/iso4217USDiso42170u001Standardhttp://www.xbrl.org/2003/instancesharesxbrli0u002Dividehttp://www.xbrl.org/2003/iso4217USDiso4217http://www.xbrl.org/2003/instancesharesxbrli0USDUSD$2true0gas_NotesToFinancialStatementsAbstractgasfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00falsefalsefalsefalsefalseOtherxbrli:stringItemTypestringNo definition available.falsefalseNotes to Financial Statements [Abstract]3false0us-gaap_PensionAndOtherPostretirementBenefitsDisclosureTextBlockus-gaaptruenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00<div><table style="FONT-SIZE: 10pt; FONT-FAMILY: times new roman" cellspacing="0" cellpadding="0" width="100%" align="center" border="0"><tr style="LINE-HEIGHT: 1.5" valign="top"><td style="WIDTH: 18pt"><div style="MARGIN-LEFT: 0pt; TEXT-INDENT: 0pt; MARGIN-RIGHT: 0pt">9.</div></td><td><div align="left">POSTRETIREMENT BENEFITS</div></td></tr></table></div><div style="DISPLAY: block; TEXT-INDENT: 0pt; LINE-HEIGHT: 1.5"> </div><div style="DISPLAY: block; MARGIN-LEFT: 0pt; TEXT-INDENT: 0pt; LINE-HEIGHT: 1.5; MARGIN-RIGHT: 0pt" align="left">Nicor Gas maintains a noncontributory defined benefit pension plan covering substantially all employees hired prior to 1998.  Pension benefits are based on years of service and the highest average salary for management employees and job level for collectively bargained employees (referred to as pension bands).  The benefit obligation related to collectively bargained benefits considers the company’s past practice of regular benefit increases.  Nicor Gas also provides health care and life insurance benefits to eligible retired employees under a plan that includes a limit on the company’s share of cost for employees hired after 1982.</div><div style="DISPLAY: block; TEXT-INDENT: 0pt; LINE-HEIGHT: 1.5"> </div><div style="DISPLAY: block; MARGIN-LEFT: 0pt; TEXT-INDENT: 0pt; LINE-HEIGHT: 1.5; MARGIN-RIGHT: 0pt" align="left">The company’s postretirement benefit costs have historically been considered in rate proceedings in the period they are accrued.  As a regulated utility, Nicor Gas expects continued rate recovery of the eligible costs of its defined benefit postretirement plans and, accordingly, associated changes in the plan’s funded status have been deferred as a regulatory asset or liability until recognized in net income, instead of being recorded in accumulated other comprehensive income.  However, to the extent Nicor Gas employees perform services for non-regulated affiliates and to the extent such employees are eligible to participate in these plans, the affiliates are charged for the cost of these benefits and the changes in the funded status relating to these employees are recorded in accumulated other comprehensive income.</div><div style="DISPLAY: block; TEXT-INDENT: 0pt; LINE-HEIGHT: 1.5"> </div><div style="DISPLAY: block; MARGIN-LEFT: 0pt; TEXT-INDENT: 0pt; LINE-HEIGHT: 1.5; MARGIN-RIGHT: 0pt" align="left">About one-fourth of the net benefit cost related to these plans has been capitalized as a cost of constructing gas distribution facilities and the remainder is included in gas distribution operating and maintenance expense, net of amounts charged to affiliates.  Net benefit cost included the following components (in millions):</div><div style="DISPLAY: block; TEXT-INDENT: 0pt; LINE-HEIGHT: 1.5"> </div><div align="center"><table style="FONT-SIZE: 10pt; FONT-FAMILY: times new roman" cellspacing="0" cellpadding="0" width="100%"><tr><td style="PADDING-BOTTOM: 2px" valign="bottom" width="24%">  </td><td style="PADDING-BOTTOM: 2px; LINE-HEIGHT: 1.5" valign="bottom" width="1%"> </td><td style="LINE-HEIGHT: 1.5; BORDER-BOTTOM: black 2px solid" valign="bottom" width="14%" colspan="6"><div style="DISPLAY: block; MARGIN-LEFT: 0pt; TEXT-INDENT: 0pt; LINE-HEIGHT: 1.5; MARGIN-RIGHT: 0pt" align="center">Pension benefits</div></td><td style="PADDING-BOTTOM: 2px; LINE-HEIGHT: 1.5; TEXT-ALIGN: left" valign="bottom" nowrap="nowrap" width="2%"> </td><td style="PADDING-BOTTOM: 2px; LINE-HEIGHT: 1.5" valign="bottom" width="2%"> </td><td style="LINE-HEIGHT: 1.5; BORDER-BOTTOM: black 2px solid" valign="bottom" width="14%" colspan="6"><div style="DISPLAY: block; MARGIN-LEFT: 0pt; TEXT-INDENT: 0pt; LINE-HEIGHT: 1.5; MARGIN-RIGHT: 0pt" align="center">Health care and</div><div style="DISPLAY: block; MARGIN-LEFT: 0pt; TEXT-INDENT: 0pt; LINE-HEIGHT: 1.5; MARGIN-RIGHT: 0pt" align="center">other benefits</div></td><td style="PADDING-BOTTOM: 2px; LINE-HEIGHT: 1.5; TEXT-ALIGN: left" valign="bottom" nowrap="nowrap" width="1%"> </td></tr><tr><td style="PADDING-BOTTOM: 2px; LINE-HEIGHT: 1.5" valign="bottom" width="24%">  </td><td style="PADDING-BOTTOM: 2px; LINE-HEIGHT: 1.5" valign="bottom" width="1%"> </td><td style="LINE-HEIGHT: 1.5; BORDER-BOTTOM: black 2px solid" valign="bottom" width="5%" colspan="2"><div style="DISPLAY: block; MARGIN-LEFT: 0pt; TEXT-INDENT: 0pt; LINE-HEIGHT: 1.5; MARGIN-RIGHT: 0pt" align="center">2011</div></td><td style="PADDING-BOTTOM: 2px; LINE-HEIGHT: 1.5; TEXT-ALIGN: left" valign="bottom" nowrap="nowrap" width="2%"> </td><td style="PADDING-BOTTOM: 2px; LINE-HEIGHT: 1.5" valign="bottom" width="2%"> </td><td style="LINE-HEIGHT: 1.5; BORDER-BOTTOM: black 2px solid" valign="bottom" width="5%" colspan="2"><div style="DISPLAY: block; MARGIN-LEFT: 0pt; TEXT-INDENT: 0pt; LINE-HEIGHT: 1.5; MARGIN-RIGHT: 0pt" align="center">2010</div></td><td style="PADDING-BOTTOM: 2px; LINE-HEIGHT: 1.5; TEXT-ALIGN: left" valign="bottom" nowrap="nowrap" width="2%"> </td><td style="PADDING-BOTTOM: 2px; LINE-HEIGHT: 1.5" valign="bottom" width="2%"> </td><td style="LINE-HEIGHT: 1.5; BORDER-BOTTOM: black 2px solid" valign="bottom" width="5%" colspan="2"><div style="DISPLAY: block; MARGIN-LEFT: 0pt; TEXT-INDENT: 0pt; LINE-HEIGHT: 1.5; MARGIN-RIGHT: 0pt" align="center">2011</div></td><td style="PADDING-BOTTOM: 2px; LINE-HEIGHT: 1.5; TEXT-ALIGN: left" valign="bottom" nowrap="nowrap" width="2%"> </td><td style="PADDING-BOTTOM: 2px; LINE-HEIGHT: 1.5" valign="bottom" width="2%"> </td><td style="LINE-HEIGHT: 1.5; BORDER-BOTTOM: black 2px solid" valign="bottom" width="5%" colspan="2"><div style="DISPLAY: block; MARGIN-LEFT: 0pt; TEXT-INDENT: 0pt; LINE-HEIGHT: 1.5; MARGIN-RIGHT: 0pt" align="center">2010</div></td><td style="PADDING-BOTTOM: 2px; LINE-HEIGHT: 1.5; TEXT-ALIGN: left" valign="bottom" nowrap="nowrap" width="1%"> </td></tr><tr bgcolor="#e2eef5"><td style="LINE-HEIGHT: 1.5" valign="bottom" align="left" width="24%"><div style="DISPLAY: block; MARGIN-LEFT: 0pt; TEXT-INDENT: 0pt; LINE-HEIGHT: 1.5; MARGIN-RIGHT: 0pt" align="left">Three months ended March 31</div></td><td style="LINE-HEIGHT: 1.5" valign="bottom" width="1%"> </td><td style="LINE-HEIGHT: 1.5" valign="bottom" width="5%" colspan="2"> </td><td style="LINE-HEIGHT: 1.5; TEXT-ALIGN: left" valign="bottom" nowrap="nowrap" width="2%"> </td><td style="LINE-HEIGHT: 1.5" valign="bottom" width="2%"> </td><td style="LINE-HEIGHT: 1.5" valign="bottom" width="5%" colspan="2"> </td><td style="LINE-HEIGHT: 1.5; TEXT-ALIGN: left" valign="bottom" nowrap="nowrap" width="2%"> </td><td style="LINE-HEIGHT: 1.5" valign="bottom" width="2%"> </td><td style="LINE-HEIGHT: 1.5" valign="bottom" width="5%" colspan="2"> </td><td style="LINE-HEIGHT: 1.5; TEXT-ALIGN: left" valign="bottom" nowrap="nowrap" width="2%"> </td><td style="LINE-HEIGHT: 1.5" valign="bottom" width="2%"> </td><td style="LINE-HEIGHT: 1.5" valign="bottom" width="5%" colspan="2"> </td><td style="LINE-HEIGHT: 1.5; TEXT-ALIGN: left" valign="bottom" nowrap="nowrap" width="1%"> </td></tr><tr bgcolor="white"><td style="LINE-HEIGHT: 1.5" valign="bottom" align="left" width="24%"><div style="DISPLAY: block; MARGIN-LEFT: 18pt; TEXT-INDENT: 0pt; LINE-HEIGHT: 1.5; MARGIN-RIGHT: 0pt" align="left">Service cost</div></td><td style="LINE-HEIGHT: 1.5" valign="bottom" align="left" width="1%"> </td><td style="LINE-HEIGHT: 1.5; TEXT-ALIGN: left" valign="bottom" width="1%">$</td><td style="LINE-HEIGHT: 1.5; TEXT-ALIGN: right" valign="bottom" width="4%">2.5</td><td style="LINE-HEIGHT: 1.5; TEXT-ALIGN: left" valign="bottom" nowrap="nowrap" width="2%"> </td><td style="LINE-HEIGHT: 1.5" valign="bottom" align="left" width="2%"> </td><td style="LINE-HEIGHT: 1.5; TEXT-ALIGN: left" valign="bottom" width="1%">$</td><td style="LINE-HEIGHT: 1.5; TEXT-ALIGN: right" valign="bottom" width="4%">2.4</td><td style="LINE-HEIGHT: 1.5; TEXT-ALIGN: left" valign="bottom" nowrap="nowrap" width="2%"> </td><td style="LINE-HEIGHT: 1.5" valign="bottom" align="left" width="2%"> </td><td style="LINE-HEIGHT: 1.5; TEXT-ALIGN: left" valign="bottom" width="1%">$</td><td style="LINE-HEIGHT: 1.5; TEXT-ALIGN: right" valign="bottom" width="4%">.6</td><td style="LINE-HEIGHT: 1.5; TEXT-ALIGN: left" valign="bottom" nowrap="nowrap" width="2%"> </td><td style="LINE-HEIGHT: 1.5" valign="bottom" align="left" width="2%"> </td><td style="LINE-HEIGHT: 1.5; TEXT-ALIGN: left" valign="bottom" width="1%">$</td><td style="LINE-HEIGHT: 1.5; TEXT-ALIGN: right" valign="bottom" width="4%">.6</td><td style="LINE-HEIGHT: 1.5; TEXT-ALIGN: left" valign="bottom" nowrap="nowrap" width="1%"> </td></tr><tr bgcolor="#e2eef5"><td style="LINE-HEIGHT: 1.5" valign="bottom" align="left" width="24%"><div style="DISPLAY: block; MARGIN-LEFT: 18pt; TEXT-INDENT: 0pt; LINE-HEIGHT: 1.5; MARGIN-RIGHT: 0pt" align="left">Interest cost</div></td><td style="LINE-HEIGHT: 1.5" valign="bottom" align="left" width="1%"> </td><td style="LINE-HEIGHT: 1.5; TEXT-ALIGN: left" valign="bottom" width="1%"> </td><td style="LINE-HEIGHT: 1.5; TEXT-ALIGN: right" valign="bottom" width="4%">4.1</td><td style="LINE-HEIGHT: 1.5; TEXT-ALIGN: left" valign="bottom" nowrap="nowrap" width="2%"> </td><td style="LINE-HEIGHT: 1.5" valign="bottom" align="left" width="2%"> </td><td style="LINE-HEIGHT: 1.5; TEXT-ALIGN: left" valign="bottom" width="1%"> </td><td style="LINE-HEIGHT: 1.5; TEXT-ALIGN: right" valign="bottom" width="4%">4.0</td><td style="LINE-HEIGHT: 1.5; TEXT-ALIGN: left" valign="bottom" nowrap="nowrap" width="2%"> </td><td style="LINE-HEIGHT: 1.5" valign="bottom" align="left" width="2%"> </td><td style="LINE-HEIGHT: 1.5; TEXT-ALIGN: left" valign="bottom" width="1%"> </td><td style="LINE-HEIGHT: 1.5; TEXT-ALIGN: right" valign="bottom" width="4%">3.1</td><td style="LINE-HEIGHT: 1.5; TEXT-ALIGN: left" valign="bottom" nowrap="nowrap" width="2%"> </td><td style="LINE-HEIGHT: 1.5" valign="bottom" align="left" width="2%"> </td><td style="LINE-HEIGHT: 1.5; TEXT-ALIGN: left" valign="bottom" width="1%"> </td><td style="LINE-HEIGHT: 1.5; TEXT-ALIGN: right" valign="bottom" width="4%">3.0</td><td style="LINE-HEIGHT: 1.5; TEXT-ALIGN: left" valign="bottom" nowrap="nowrap" width="1%"> </td></tr><tr bgcolor="white"><td style="LINE-HEIGHT: 1.5" valign="bottom" align="left" width="24%"><div style="DISPLAY: block; MARGIN-LEFT: 18pt; TEXT-INDENT: 0pt; LINE-HEIGHT: 1.5; MARGIN-RIGHT: 0pt" align="left">Expected return on plan assets</div></td><td style="LINE-HEIGHT: 1.5" valign="bottom" align="left" width="1%"> </td><td style="LINE-HEIGHT: 1.5; TEXT-ALIGN: left" valign="bottom" width="1%"> </td><td style="LINE-HEIGHT: 1.5; TEXT-ALIGN: right" valign="bottom" width="4%">(7.8</td><td style="LINE-HEIGHT: 1.5; TEXT-ALIGN: left" valign="bottom" nowrap="nowrap" width="2%">)</td><td style="LINE-HEIGHT: 1.5" valign="bottom" align="left" width="2%"> </td><td style="LINE-HEIGHT: 1.5; TEXT-ALIGN: left" valign="bottom" width="1%"> </td><td style="LINE-HEIGHT: 1.5; TEXT-ALIGN: right" valign="bottom" width="4%">(7.2</td><td style="LINE-HEIGHT: 1.5; TEXT-ALIGN: left" valign="bottom" nowrap="nowrap" width="2%">)</td><td style="LINE-HEIGHT: 1.5" valign="bottom" align="left" width="2%"> </td><td style="LINE-HEIGHT: 1.5; TEXT-ALIGN: left" valign="bottom" width="1%"> </td><td style="LINE-HEIGHT: 1.5; TEXT-ALIGN: right" valign="bottom" width="4%">-</td><td style="LINE-HEIGHT: 1.5; TEXT-ALIGN: left" valign="bottom" nowrap="nowrap" width="2%"> </td><td style="LINE-HEIGHT: 1.5" valign="bottom" align="left" width="2%"> </td><td style="LINE-HEIGHT: 1.5; TEXT-ALIGN: left" valign="bottom" width="1%"> </td><td style="LINE-HEIGHT: 1.5; TEXT-ALIGN: right" valign="bottom" width="4%">-</td><td style="LINE-HEIGHT: 1.5; TEXT-ALIGN: left" valign="bottom" nowrap="nowrap" width="1%"> </td></tr><tr bgcolor="#e2eef5"><td style="LINE-HEIGHT: 1.5" valign="bottom" align="left" width="24%"><div style="DISPLAY: block; MARGIN-LEFT: 18pt; TEXT-INDENT: 0pt; LINE-HEIGHT: 1.5; MARGIN-RIGHT: 0pt" align="left">Recognized net actuarial loss</div></td><td style="LINE-HEIGHT: 1.5" valign="bottom" align="left" width="1%"> </td><td style="LINE-HEIGHT: 1.5; TEXT-ALIGN: left" valign="bottom" width="1%"> </td><td style="LINE-HEIGHT: 1.5; TEXT-ALIGN: right" valign="bottom" width="4%">2.4</td><td style="LINE-HEIGHT: 1.5; TEXT-ALIGN: left" valign="bottom" nowrap="nowrap" width="2%"> </td><td style="LINE-HEIGHT: 1.5" valign="bottom" align="left" width="2%"> </td><td style="LINE-HEIGHT: 1.5; TEXT-ALIGN: left" valign="bottom" width="1%"> </td><td style="LINE-HEIGHT: 1.5; TEXT-ALIGN: right" valign="bottom" width="4%">3.0</td><td style="LINE-HEIGHT: 1.5; TEXT-ALIGN: left" valign="bottom" nowrap="nowrap" width="2%"> </td><td style="LINE-HEIGHT: 1.5" valign="bottom" align="left" width="2%"> </td><td style="LINE-HEIGHT: 1.5; TEXT-ALIGN: left" valign="bottom" width="1%"> </td><td style="LINE-HEIGHT: 1.5; TEXT-ALIGN: right" valign="bottom" width="4%">1.5</td><td style="LINE-HEIGHT: 1.5; TEXT-ALIGN: left" valign="bottom" nowrap="nowrap" width="2%"> </td><td style="LINE-HEIGHT: 1.5" valign="bottom" align="left" width="2%"> </td><td style="LINE-HEIGHT: 1.5; TEXT-ALIGN: left" valign="bottom" width="1%"> </td><td style="LINE-HEIGHT: 1.5; TEXT-ALIGN: right" valign="bottom" width="4%">1.0</td><td style="LINE-HEIGHT: 1.5; TEXT-ALIGN: left" valign="bottom" nowrap="nowrap" width="1%"> </td></tr><tr bgcolor="white"><td style="PADDING-BOTTOM: 2px; LINE-HEIGHT: 1.5" valign="bottom" align="left" width="24%"><div style="DISPLAY: block; MARGIN-LEFT: 18pt; TEXT-INDENT: 0pt; LINE-HEIGHT: 1.5; MARGIN-RIGHT: 0pt" align="left">Amortization of prior service cost</div></td><td style="PADDING-BOTTOM: 2px; LINE-HEIGHT: 1.5" valign="bottom" align="left" width="1%"> </td><td style="LINE-HEIGHT: 1.5; BORDER-BOTTOM: black 2px solid; TEXT-ALIGN: left" valign="bottom" width="1%"> </td><td style="LINE-HEIGHT: 1.5; BORDER-BOTTOM: black 2px solid; TEXT-ALIGN: right" valign="bottom" width="4%">.1</td><td style="PADDING-BOTTOM: 2px; LINE-HEIGHT: 1.5; TEXT-ALIGN: left" valign="bottom" nowrap="nowrap" width="2%"> </td><td style="PADDING-BOTTOM: 2px; LINE-HEIGHT: 1.5" valign="bottom" align="left" width="2%"> </td><td style="LINE-HEIGHT: 1.5; BORDER-BOTTOM: black 2px solid; TEXT-ALIGN: left" valign="bottom" width="1%"> </td><td style="LINE-HEIGHT: 1.5; BORDER-BOTTOM: black 2px solid; TEXT-ALIGN: right" valign="bottom" width="4%">.1</td><td style="PADDING-BOTTOM: 2px; LINE-HEIGHT: 1.5; TEXT-ALIGN: left" valign="bottom" nowrap="nowrap" width="2%"> </td><td style="PADDING-BOTTOM: 2px; LINE-HEIGHT: 1.5" valign="bottom" align="left" width="2%"> </td><td style="LINE-HEIGHT: 1.5; BORDER-BOTTOM: black 2px solid; TEXT-ALIGN: left" valign="bottom" width="1%"> </td><td style="LINE-HEIGHT: 1.5; BORDER-BOTTOM: black 2px solid; TEXT-ALIGN: right" valign="bottom" width="4%">-</td><td style="PADDING-BOTTOM: 2px; LINE-HEIGHT: 1.5; TEXT-ALIGN: left" valign="bottom" nowrap="nowrap" width="2%"> </td><td style="PADDING-BOTTOM: 2px; LINE-HEIGHT: 1.5" valign="bottom" align="left" width="2%"> </td><td style="LINE-HEIGHT: 1.5; BORDER-BOTTOM: black 2px solid; TEXT-ALIGN: left" valign="bottom" width="1%"> </td><td style="LINE-HEIGHT: 1.5; BORDER-BOTTOM: black 2px solid; TEXT-ALIGN: right" valign="bottom" width="4%">-</td><td style="PADDING-BOTTOM: 2px; LINE-HEIGHT: 1.5; TEXT-ALIGN: left" valign="bottom" nowrap="nowrap" width="1%"> </td></tr><tr bgcolor="#e2eef5"><td style="PADDING-BOTTOM: 4px; LINE-HEIGHT: 1.5" valign="bottom" align="left" width="24%"><div style="DISPLAY: block; MARGIN-LEFT: 18pt; TEXT-INDENT: 0pt; LINE-HEIGHT: 1.5; MARGIN-RIGHT: 0pt" align="left">Net benefit cost</div></td><td style="PADDING-BOTTOM: 4px; LINE-HEIGHT: 1.5" valign="bottom" align="left" width="1%"> </td><td style="LINE-HEIGHT: 1.5; BORDER-BOTTOM: black 4px double; TEXT-ALIGN: left" valign="bottom" width="1%">$</td><td style="LINE-HEIGHT: 1.5; BORDER-BOTTOM: black 4px double; TEXT-ALIGN: right" valign="bottom" width="4%">1.3</td><td style="PADDING-BOTTOM: 4px; LINE-HEIGHT: 1.5; TEXT-ALIGN: left" valign="bottom" nowrap="nowrap" width="2%"> </td><td style="PADDING-BOTTOM: 4px; LINE-HEIGHT: 1.5" valign="bottom" align="left" width="2%"> </td><td style="LINE-HEIGHT: 1.5; BORDER-BOTTOM: black 4px double; TEXT-ALIGN: left" valign="bottom" width="1%">$</td><td style="LINE-HEIGHT: 1.5; BORDER-BOTTOM: black 4px double; TEXT-ALIGN: right" valign="bottom" width="4%">2.3</td><td style="PADDING-BOTTOM: 4px; LINE-HEIGHT: 1.5; TEXT-ALIGN: left" valign="bottom" nowrap="nowrap" width="2%"> </td><td style="PADDING-BOTTOM: 4px; LINE-HEIGHT: 1.5" valign="bottom" align="left" width="2%"> </td><td style="LINE-HEIGHT: 1.5; BORDER-BOTTOM: black 4px double; TEXT-ALIGN: left" valign="bottom" width="1%">$</td><td style="LINE-HEIGHT: 1.5; BORDER-BOTTOM: black 4px double; TEXT-ALIGN: right" valign="bottom" width="4%">5.2</td><td style="PADDING-BOTTOM: 4px; LINE-HEIGHT: 1.5; TEXT-ALIGN: left" valign="bottom" nowrap="nowrap" width="2%"> </td><td style="PADDING-BOTTOM: 4px; LINE-HEIGHT: 1.5" valign="bottom" align="left" width="2%"> </td><td style="LINE-HEIGHT: 1.5; BORDER-BOTTOM: black 4px double; TEXT-ALIGN: left" valign="bottom" width="1%">$</td><td style="LINE-HEIGHT: 1.5; BORDER-BOTTOM: black 4px double; TEXT-ALIGN: right" valign="bottom" width="4%">4.6</td><td style="PADDING-BOTTOM: 4px; LINE-HEIGHT: 1.5; TEXT-ALIGN: left" valign="bottom" nowrap="nowrap" width="1%"> </td></tr></table></div><div style="DISPLAY: block; TEXT-INDENT: 0pt; LINE-HEIGHT: 1.5"> </div><div style="DISPLAY: block; MARGIN-LEFT: 0pt; TEXT-INDENT: 0pt; LINE-HEIGHT: 1.5; MARGIN-RIGHT: 0pt" align="left">The Health Care Act contains provisions that may impact Nicor Gas’ obligation for retiree health care benefits.  The company does not currently believe these provisions will materially increase its postretirement benefit obligation, but will continue to evaluate the impact of future regulations and interpretations.</div>9.POSTRETIREMENT BENEFITSNicor Gas maintains a noncontributory defined benefit pension plan covering substantially all employees hired prior tofalsefalsefalsefalsefalseOtherus-types:textBlockItemTypestringDescription containing the entire pension and other postretirement benefits disclosure as a single block of text.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name FASB Staff Position (FSP) -Number FAS106-2 -Paragraph 20, 21, 22 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 132R -Paragraph 5, 6, 7, 8 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 87 -Paragraph 264 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Implementation Guide (Q and A) -Number FAS88 -Paragraph 63 Reference 5: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 158 -Paragraph 7, 21, 22 Reference 6: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 132R -Paragraph 5 -Subparagraph b Reference 7: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Principles Board Opinion (APB) -Number 30 -Paragraph 26 Reference 8: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 106 -Paragraph 518 Reference 9: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Emerging Issues Task Force (EITF) -Number 03-2 -Paragraph 8 Reference 10: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 132R -Paragraph 8 -Subparagraph m Reference 11: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 132R -Paragraph 5 -Subparagraph h Reference 12: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 132R -Paragraph 5 -Subparagraph a Reference 13: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 132R -Paragraph 5 -Subparagraph q falsefalsePOSTRETIREMENT BENEFITS12POSTRETIREMENT BENEFITSUnKnownUnKnownUnKnownUnKnownfalsetrue