2.2.0.25falsefalse006050 - Disclosure - ASSET RETIREMENT OBLIGATIONStruefalsefalse1falsefalseUSDfalsefalse1/1/2010 - 12/31/2010
USD ($)
USD ($) / shares
$c00032http://www.sec.gov/CIK0000072020duration2010-01-01T00:00:002010-12-31T00:00:00u000Standardhttp://www.xbrl.org/2003/iso4217USDiso42170u001Standardhttp://www.xbrl.org/2003/instancesharesxbrli0u002Dividehttp://www.xbrl.org/2003/iso4217USDiso4217http://www.xbrl.org/2003/instancesharesxbrli0USDUSD$2true0gas_NotesToFinancialStatementsAbstractgasfalsenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse| 1falsefalsefalse00falsefalsefalsefalsefalse | Otherxbrli:stringItemTypestringNo definition available.falsefalse
3false0us-gaap_AssetRetirementObligationDisclosureTextBlockus-gaaptruenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse| 1falsefalsefalse00<div style="LINE-HEIGHT: 1.5"><table style="FONT-SIZE: 10pt; FONT-FAMILY: times new roman" cellspacing="0" cellpadding="0" width="100%" align="center" border="0"><tr valign="top"><td style="WIDTH: 18pt; LINE-HEIGHT: 1.5"><div style="MARGIN-LEFT: 0pt; TEXT-INDENT: 0pt; LINE-HEIGHT: 1.5; MARGIN-RIGHT: 0pt"><font style="DISPLAY: inline; FONT-WEIGHT: bold; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman">4.</font></div></td><td style="LINE-HEIGHT: 1.5"><div style="LINE-HEIGHT: 1.5" align="left"><font style="DISPLAY: inline; FONT-WEIGHT: bold; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman">ASSET RETIREMENT OBLIGATIONS</font></div></td></tr></table></div><div style="DISPLAY: block; TEXT-INDENT: 0pt; LINE-HEIGHT: 1.5"><br /></div><div style="DISPLAY: block; MARGIN-LEFT: 0pt; TEXT-INDENT: 0pt; LINE-HEIGHT: 1.5; MARGIN-RIGHT: 0pt" align="left"><font style="DISPLAY: inline; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman">Nicor records AROs associated with services, mains and other components of the distribution system and the buildings in its gas distribution business and with certain equipment in its shipping business.  Nicor has not recognized an ARO associated with gathering lines and storage wells in its gas distribution business because there is insufficient company or industry retirement history to reasonably estimate the fair value of the obligation.</font></div><div style="DISPLAY: block; TEXT-INDENT: 0pt; LINE-HEIGHT: 1.5"><br /></div><div style="DISPLAY: block; MARGIN-LEFT: 0pt; TEXT-INDENT: 0pt; LINE-HEIGHT: 1.5; MARGIN-RIGHT: 0pt" align="left"><font style="DISPLAY: inline; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman">The following table presents a reconciliation of the beginning and ending ARO for the years ended December 31 (in millions):</font></div><div style="DISPLAY: block; TEXT-INDENT: 0pt; LINE-HEIGHT: 1.5"><br /></div><div style="LINE-HEIGHT: 1.5" align="center"><table style="FONT-SIZE: 10pt; LINE-HEIGHT: 1.5; FONT-FAMILY: times new roman" cellspacing="0" cellpadding="0" width="100%"><tr style="LINE-HEIGHT: 1.5"><td style="PADDING-BOTTOM: 2px; LINE-HEIGHT: 1.5" valign="bottom" width="32%"><font style="DISPLAY: inline; FONT-SIZE: 10pt; FONT-FAMILY: times new roman">  </font></td><td style="PADDING-BOTTOM: 2px; LINE-HEIGHT: 1.5" valign="bottom" width="1%"><font style="DISPLAY: inline; FONT-WEIGHT: bold; FONT-SIZE: 10pt; FONT-FAMILY: times new roman"> </font></td><td style="LINE-HEIGHT: 1.5; BORDER-BOTTOM: black 2px solid" valign="bottom" width="7%" colspan="2"><div style="LINE-HEIGHT: 1.5" align="center"><font style="DISPLAY: inline; FONT-WEIGHT: bold; FONT-SIZE: 10pt; FONT-FAMILY: times new roman">2010</font></div></td><td style="PADDING-BOTTOM: 2px; LINE-HEIGHT: 1.5; TEXT-ALIGN: left" valign="bottom" nowrap="nowrap" width="1%"><font style="DISPLAY: inline; FONT-WEIGHT: bold; FONT-SIZE: 10pt; FONT-FAMILY: times new roman"> </font></td><td style="PADDING-BOTTOM: 2px; LINE-HEIGHT: 1.5" valign="bottom" width="1%"><font style="DISPLAY: inline; FONT-SIZE: 10pt; FONT-FAMILY: times new roman"> </font></td><td style="LINE-HEIGHT: 1.5; BORDER-BOTTOM: black 2px solid" valign="bottom" width="7%" colspan="2"><div style="LINE-HEIGHT: 1.5" align="center"><font style="DISPLAY: inline; FONT-SIZE: 10pt; FONT-FAMILY: times new roman">2009</font></div></td><td style="PADDING-BOTTOM: 2px; LINE-HEIGHT: 1.5; TEXT-ALIGN: left" valign="bottom" nowrap="nowrap" width="1%"><font style="DISPLAY: inline; FONT-SIZE: 10pt; FONT-FAMILY: times new roman"> </font></td></tr><tr><td style="LINE-HEIGHT: 1.5" valign="bottom" width="32%"><font style="DISPLAY: inline; FONT-SIZE: 10pt; FONT-FAMILY: times new roman">  </font></td><td style="LINE-HEIGHT: 1.5" valign="bottom" width="1%"><font style="DISPLAY: inline; FONT-SIZE: 10pt; FONT-FAMILY: times new roman"> </font></td><td style="LINE-HEIGHT: 1.5" valign="bottom" width="7%" colspan="2"><font style="DISPLAY: inline; FONT-SIZE: 10pt; FONT-FAMILY: times new roman"> </font></td><td style="LINE-HEIGHT: 1.5; TEXT-ALIGN: left" valign="bottom" nowrap="nowrap" width="1%"><font style="DISPLAY: inline; FONT-SIZE: 10pt; FONT-FAMILY: times new roman"> </font></td><td style="LINE-HEIGHT: 1.5" valign="bottom" width="1%"><font style="DISPLAY: inline; FONT-SIZE: 10pt; FONT-FAMILY: times new roman"> </font></td><td style="LINE-HEIGHT: 1.5" valign="bottom" width="7%" colspan="2"><font style="DISPLAY: inline; FONT-SIZE: 10pt; FONT-FAMILY: times new roman"> </font></td><td style="LINE-HEIGHT: 1.5; TEXT-ALIGN: left" valign="bottom" nowrap="nowrap" width="1%"><font style="DISPLAY: inline; FONT-SIZE: 10pt; FONT-FAMILY: times new roman"> </font></td></tr><tr><td style="LINE-HEIGHT: 1.5" valign="bottom" align="left" width="32%"><div style="DISPLAY: block; MARGIN-LEFT: 0pt; TEXT-INDENT: 0pt; LINE-HEIGHT: 1.5; MARGIN-RIGHT: 0pt" align="left"><font style="DISPLAY: inline; FONT-SIZE: 10pt; FONT-FAMILY: times new roman">Beginning of period</font></div></td><td style="LINE-HEIGHT: 1.5" valign="bottom" align="left" width="1%"><font style="DISPLAY: inline; FONT-WEIGHT: bold; FONT-SIZE: 10pt; FONT-FAMILY: times new roman"> </font></td><td style="LINE-HEIGHT: 1.5; TEXT-ALIGN: left" valign="bottom" width="1%"><font style="DISPLAY: inline; FONT-WEIGHT: bold; FONT-SIZE: 10pt; FONT-FAMILY: times new roman">$</font></td><td style="LINE-HEIGHT: 1.5; TEXT-ALIGN: right" valign="bottom" width="6%"><font style="DISPLAY: inline; FONT-WEIGHT: bold; FONT-SIZE: 10pt; FONT-FAMILY: times new roman">192.2</font></td><td style="LINE-HEIGHT: 1.5; TEXT-ALIGN: left" valign="bottom" nowrap="nowrap" width="1%"><font style="DISPLAY: inline; FONT-WEIGHT: bold; FONT-SIZE: 10pt; FONT-FAMILY: times new roman"> </font></td><td style="LINE-HEIGHT: 1.5" valign="bottom" align="left" width="1%"><font style="DISPLAY: inline; FONT-SIZE: 10pt; FONT-FAMILY: times new roman"> </font></td><td style="LINE-HEIGHT: 1.5; TEXT-ALIGN: left" valign="bottom" width="1%"><font style="DISPLAY: inline; FONT-SIZE: 10pt; FONT-FAMILY: times new roman">$</font></td><td style="LINE-HEIGHT: 1.5; TEXT-ALIGN: right" valign="bottom" width="6%"><font style="DISPLAY: inline; FONT-SIZE: 10pt; FONT-FAMILY: times new roman">187.2</font></td><td style="LINE-HEIGHT: 1.5; TEXT-ALIGN: left" valign="bottom" nowrap="nowrap" width="1%"><font style="DISPLAY: inline; FONT-SIZE: 10pt; FONT-FAMILY: times new roman"> </font></td></tr><tr bgcolor="#e2eef5"><td style="LINE-HEIGHT: 1.5" valign="bottom" align="left" width="32%"><div style="DISPLAY: block; MARGIN-LEFT: 0pt; TEXT-INDENT: 18pt; LINE-HEIGHT: 1.5; MARGIN-RIGHT: 0pt" align="left"><font style="DISPLAY: inline; FONT-SIZE: 10pt; FONT-FAMILY: times new roman">Liabilities incurred during the period</font></div></td><td style="LINE-HEIGHT: 1.5" valign="bottom" align="left" width="1%"><font style="DISPLAY: inline; FONT-WEIGHT: bold; FONT-SIZE: 10pt; FONT-FAMILY: times new roman"> </font></td><td style="LINE-HEIGHT: 1.5; TEXT-ALIGN: left" valign="bottom" width="1%"><font style="DISPLAY: inline; FONT-WEIGHT: bold; FONT-SIZE: 10pt; FONT-FAMILY: times new roman"> </font></td><td style="LINE-HEIGHT: 1.5; TEXT-ALIGN: right" valign="bottom" width="6%"><font style="DISPLAY: inline; FONT-WEIGHT: bold; FONT-SIZE: 10pt; FONT-FAMILY: times new roman"><font style="MARGIN-LEFT: 15.85pt"></font>2.1</font></td><td style="LINE-HEIGHT: 1.5; TEXT-ALIGN: left" valign="bottom" nowrap="nowrap" width="1%"><font style="DISPLAY: inline; FONT-WEIGHT: bold; FONT-SIZE: 10pt; FONT-FAMILY: times new roman"> </font></td><td style="LINE-HEIGHT: 1.5" valign="bottom" align="left" width="1%"><font style="DISPLAY: inline; FONT-SIZE: 10pt; FONT-FAMILY: times new roman"> </font></td><td style="LINE-HEIGHT: 1.5; TEXT-ALIGN: left" valign="bottom" width="1%"><font style="DISPLAY: inline; FONT-SIZE: 10pt; FONT-FAMILY: times new roman"> </font></td><td style="LINE-HEIGHT: 1.5; TEXT-ALIGN: right" valign="bottom" width="6%"><font style="DISPLAY: inline; FONT-SIZE: 10pt; FONT-FAMILY: times new roman"><font style="MARGIN-LEFT: 15.1pt"></font>2.1</font></td><td style="LINE-HEIGHT: 1.5; TEXT-ALIGN: left" valign="bottom" nowrap="nowrap" width="1%"><font style="DISPLAY: inline; FONT-SIZE: 10pt; FONT-FAMILY: times new roman"> </font></td></tr><tr bgcolor="white"><td style="LINE-HEIGHT: 1.5" valign="bottom" align="left" width="32%"><div style="DISPLAY: block; MARGIN-LEFT: 0pt; TEXT-INDENT: 18pt; LINE-HEIGHT: 1.5; MARGIN-RIGHT: 0pt" align="left"><font style="DISPLAY: inline; FONT-SIZE: 10pt; FONT-FAMILY: times new roman">Liabilities settled during the period</font></div></td><td style="LINE-HEIGHT: 1.5" valign="bottom" align="left" width="1%"><font style="DISPLAY: inline; FONT-WEIGHT: bold; FONT-SIZE: 10pt; FONT-FAMILY: times new roman"> </font></td><td style="LINE-HEIGHT: 1.5; TEXT-ALIGN: left" valign="bottom" width="1%"><font style="DISPLAY: inline; FONT-WEIGHT: bold; FONT-SIZE: 10pt; FONT-FAMILY: times new roman"> </font></td><td style="LINE-HEIGHT: 1.5; TEXT-ALIGN: right" valign="bottom" width="6%"><font style="DISPLAY: inline; FONT-WEIGHT: bold; FONT-SIZE: 10pt; FONT-FAMILY: times new roman"><font style="MARGIN-LEFT: 11.4pt"></font>(4.1</font></td><td style="LINE-HEIGHT: 1.5; TEXT-ALIGN: left" valign="bottom" nowrap="nowrap" width="1%"><font style="DISPLAY: inline; FONT-WEIGHT: bold; FONT-SIZE: 10pt; FONT-FAMILY: times new roman">)</font></td><td style="LINE-HEIGHT: 1.5" valign="bottom" align="left" width="1%"><font style="DISPLAY: inline; FONT-SIZE: 10pt; FONT-FAMILY: times new roman"> </font></td><td style="LINE-HEIGHT: 1.5; TEXT-ALIGN: left" valign="bottom" width="1%"><font style="DISPLAY: inline; FONT-SIZE: 10pt; FONT-FAMILY: times new roman"> </font></td><td style="LINE-HEIGHT: 1.5; TEXT-ALIGN: right" valign="bottom" width="6%"><font style="DISPLAY: inline; FONT-SIZE: 10pt; FONT-FAMILY: times new roman"><font style="MARGIN-LEFT: 10.65pt"></font>(6.3</font></td><td style="LINE-HEIGHT: 1.5; TEXT-ALIGN: left" valign="bottom" nowrap="nowrap" width="1%"><font style="DISPLAY: inline; FONT-SIZE: 10pt; FONT-FAMILY: times new roman">)</font></td></tr><tr bgcolor="#e2eef5"><td style="LINE-HEIGHT: 1.5" valign="bottom" align="left" width="32%"><div style="DISPLAY: block; MARGIN-LEFT: 0pt; TEXT-INDENT: 18pt; LINE-HEIGHT: 1.5; MARGIN-RIGHT: 0pt" align="left"><font style="DISPLAY: inline; FONT-SIZE: 10pt; FONT-FAMILY: times new roman">Accretion</font></div></td><td style="LINE-HEIGHT: 1.5" valign="bottom" align="left" width="1%"><font style="DISPLAY: inline; FONT-WEIGHT: bold; FONT-SIZE: 10pt; FONT-FAMILY: times new roman"> </font></td><td style="LINE-HEIGHT: 1.5; TEXT-ALIGN: left" valign="bottom" width="1%"><font style="DISPLAY: inline; FONT-WEIGHT: bold; FONT-SIZE: 10pt; FONT-FAMILY: times new roman"> </font></td><td style="LINE-HEIGHT: 1.5; TEXT-ALIGN: right" valign="bottom" width="6%"><font style="DISPLAY: inline; FONT-WEIGHT: bold; FONT-SIZE: 10pt; FONT-FAMILY: times new roman"><font style="MARGIN-LEFT: 9.2pt"></font>11.0</font></td><td style="LINE-HEIGHT: 1.5; TEXT-ALIGN: left" valign="bottom" nowrap="nowrap" width="1%"><font style="DISPLAY: inline; FONT-WEIGHT: bold; FONT-SIZE: 10pt; FONT-FAMILY: times new roman"> </font></td><td style="LINE-HEIGHT: 1.5" valign="bottom" align="left" width="1%"><font style="DISPLAY: inline; FONT-SIZE: 10pt; FONT-FAMILY: times new roman"> </font></td><td style="LINE-HEIGHT: 1.5; TEXT-ALIGN: left" valign="bottom" width="1%"><font style="DISPLAY: inline; FONT-SIZE: 10pt; FONT-FAMILY: times new roman"> </font></td><td style="LINE-HEIGHT: 1.5; TEXT-ALIGN: right" valign="bottom" width="6%"><font style="DISPLAY: inline; FONT-SIZE: 10pt; FONT-FAMILY: times new roman"><font style="MARGIN-LEFT: 8.45pt"></font>10.8</font></td><td style="LINE-HEIGHT: 1.5; TEXT-ALIGN: left" valign="bottom" nowrap="nowrap" width="1%"><font style="DISPLAY: inline; FONT-SIZE: 10pt; FONT-FAMILY: times new roman"> </font></td></tr><tr bgcolor="white"><td style="PADDING-BOTTOM: 2px; LINE-HEIGHT: 1.5" valign="bottom" align="left" width="32%"><div style="DISPLAY: block; MARGIN-LEFT: 0pt; TEXT-INDENT: 18pt; LINE-HEIGHT: 1.5; MARGIN-RIGHT: 0pt" align="left"><font style="DISPLAY: inline; FONT-SIZE: 10pt; FONT-FAMILY: times new roman">Revision in estimated cash flows</font></div></td><td style="PADDING-BOTTOM: 2px; LINE-HEIGHT: 1.5" valign="bottom" align="left" width="1%"><font style="DISPLAY: inline; FONT-WEIGHT: bold; FONT-SIZE: 10pt; FONT-FAMILY: times new roman"> </font></td><td style="LINE-HEIGHT: 1.5; BORDER-BOTTOM: black 2px solid; TEXT-ALIGN: left" valign="bottom" width="1%"><font style="DISPLAY: inline; FONT-WEIGHT: bold; FONT-SIZE: 10pt; FONT-FAMILY: times new roman"> </font></td><td style="LINE-HEIGHT: 1.5; BORDER-BOTTOM: black 2px solid; TEXT-ALIGN: right" valign="bottom" width="6%"><font style="DISPLAY: inline; FONT-WEIGHT: bold; FONT-SIZE: 10pt; FONT-FAMILY: times new roman"><font style="MARGIN-LEFT: 11.4pt"></font>(9.8</font></td><td style="PADDING-BOTTOM: 2px; LINE-HEIGHT: 1.5; TEXT-ALIGN: left" valign="bottom" nowrap="nowrap" width="1%"><font style="DISPLAY: inline; FONT-WEIGHT: bold; FONT-SIZE: 10pt; FONT-FAMILY: times new roman">)</font></td><td style="PADDING-BOTTOM: 2px; LINE-HEIGHT: 1.5" valign="bottom" align="left" width="1%"><font style="DISPLAY: inline; FONT-SIZE: 10pt; FONT-FAMILY: times new roman"> </font></td><td style="LINE-HEIGHT: 1.5; BORDER-BOTTOM: black 2px solid; TEXT-ALIGN: left" valign="bottom" width="1%"><font style="DISPLAY: inline; FONT-SIZE: 10pt; FONT-FAMILY: times new roman"> </font></td><td style="LINE-HEIGHT: 1.5; BORDER-BOTTOM: black 2px solid; TEXT-ALIGN: right" valign="bottom" width="6%"><font style="DISPLAY: inline; FONT-SIZE: 10pt; FONT-FAMILY: times new roman"><font style="MARGIN-LEFT: 10.65pt"></font>(1.6</font></td><td style="PADDING-BOTTOM: 2px; LINE-HEIGHT: 1.5; TEXT-ALIGN: left" valign="bottom" nowrap="nowrap" width="1%"><font style="DISPLAY: inline; FONT-SIZE: 10pt; FONT-FAMILY: times new roman">)</font></td></tr><tr bgcolor="#e2eef5"><td style="PADDING-BOTTOM: 4px; LINE-HEIGHT: 1.5" valign="bottom" align="left" width="32%"><div style="DISPLAY: block; MARGIN-LEFT: 0pt; TEXT-INDENT: 0pt; LINE-HEIGHT: 1.5; MARGIN-RIGHT: 0pt" align="left"><font style="DISPLAY: inline; FONT-SIZE: 10pt; FONT-FAMILY: times new roman">End of period</font></div></td><td style="PADDING-BOTTOM: 4px; LINE-HEIGHT: 1.5" valign="bottom" align="left" width="1%"><font style="DISPLAY: inline; FONT-WEIGHT: bold; FONT-SIZE: 10pt; FONT-FAMILY: times new roman"> </font></td><td style="LINE-HEIGHT: 1.5; BORDER-BOTTOM: black 4px double; TEXT-ALIGN: left" valign="bottom" width="1%"><font style="DISPLAY: inline; FONT-WEIGHT: bold; FONT-SIZE: 10pt; FONT-FAMILY: times new roman">$</font></td><td style="LINE-HEIGHT: 1.5; BORDER-BOTTOM: black 4px double; TEXT-ALIGN: right" valign="bottom" width="6%"><font style="DISPLAY: inline; FONT-WEIGHT: bold; FONT-SIZE: 10pt; FONT-FAMILY: times new roman">191.4</font></td><td style="PADDING-BOTTOM: 4px; LINE-HEIGHT: 1.5; TEXT-ALIGN: left" valign="bottom" nowrap="nowrap" width="1%"><font style="DISPLAY: inline; FONT-WEIGHT: bold; FONT-SIZE: 10pt; FONT-FAMILY: times new roman"> </font></td><td style="PADDING-BOTTOM: 4px; LINE-HEIGHT: 1.5" valign="bottom" align="left" width="1%"><font style="DISPLAY: inline; FONT-SIZE: 10pt; FONT-FAMILY: times new roman"> </font></td><td style="LINE-HEIGHT: 1.5; BORDER-BOTTOM: black 4px double; TEXT-ALIGN: left" valign="bottom" width="1%"><font style="DISPLAY: inline; FONT-SIZE: 10pt; FONT-FAMILY: times new roman">$</font></td><td style="LINE-HEIGHT: 1.5; BORDER-BOTTOM: black 4px double; TEXT-ALIGN: right" valign="bottom" width="6%"><font style="DISPLAY: inline; FONT-SIZE: 10pt; FONT-FAMILY: times new roman">192.2</font></td><td style="PADDING-BOTTOM: 4px; LINE-HEIGHT: 1.5; TEXT-ALIGN: left" valign="bottom" nowrap="nowrap" width="1%"><font style="DISPLAY: inline; FONT-SIZE: 10pt; FONT-FAMILY: times new roman"> </font></td></tr></table></div><div style="DISPLAY: block; TEXT-INDENT: 0pt; LINE-HEIGHT: 1.5"><br /></div><div style="DISPLAY: block; MARGIN-LEFT: 0pt; TEXT-INDENT: 0pt; LINE-HEIGHT: 1.5; MARGIN-RIGHT: 0pt" align="left"><font style="DISPLAY: inline; FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman">Substantially all of the ARO is classified as a noncurrent liability.</font></div>4.ASSET RETIREMENT OBLIGATIONSNicor records AROs associated with services, mains and other components of the distribution system and the buildings in its gasfalsefalsefalsefalsefalse | Otherus-types:textBlockItemTypestringDescription of the asset retirement obligation and the associated long-lived asset. An asset retirement obligation is a legal obligation associated with the disposal or retirement from service of a tangible long-lived asset that results from the acquisition, construction or development, or the normal operations of a long-lived asset, except for certain obligations of lessees. This element may be used for all the disclosures related to asset retirement obligations.Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 143
-Paragraph 22
falsefalse
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