XML 22 R25.htm IDEA: XBRL DOCUMENT
v2.4.0.8

Accrued Capping, Closure and Post Closure (Tables) | 6 Months Ended
--- | ---
Oct. 31, 2014
Asset Retirement Obligation Disclosure [Abstract] |
Changes to Accrued Capping, Closure and Post-Closure Liabilities | The changes to accrued final capping, closure and post-closure liabilities for the six months ended October 31, 2014 and 2013 are as follows:
|  | Six Months Ended October 31, |
|  | 2014 |  |  | 2013 |
Beginning balance |  | $ | 44,654 |  |  | $ | 43,170 |
Obligations incurred |  |  | 2,018 |  |  |  | 1,918 |
Accretion expense |  |  | 1,683 |  |  |  | 1,999 |
Payments |  |  | (4,077 | ) |  |  | (1,106 | )
Ending balance |  | $ | 44,278 |  |  | $ | 45,981 |

X
- Details
Name: | us-gaap_AssetRetirementObligationDisclosureAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Tabular disclosure of the changes in carrying amount of a liability for asset retirement obligations, for changes such as new obligations, changes in estimates of existing obligations, spending on existing obligations, property dispositions, and foreign currency translation. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 410 -SubTopic 30 -Section 50 -Paragraph 5 -URI http://asc.fasb.org/extlink&oid=6393242&loc=d3e13201-110859 + Details
Name: | us-gaap_ScheduleOfChangeInAssetRetirementObligationTableTextBlock
Namespace Prefix: | us-gaap_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration