Unrecorded Unconditional Purchase Obligation (Details) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2013
Unrecorded Unconditional Purchase Obligation [Line Items]
Guarantor Obligations, Maximum Exposure, Undiscounted	$ 1,103,904
Purchase Commitment [Member]
Unrecorded Unconditional Purchase Obligation [Line Items]
Less than 1 year	393,709
1 - 3 years	253,025
3 - 5 years	189,138
More than 5 years	419,240
Total Purchase Obligations	1,255,112
Balance on First Anniversary [Member]
Unrecorded Unconditional Purchase Obligation [Line Items]
Guarantor Obligations, Maximum Exposure, Undiscounted	892,298
More Than One And Within Three Years From Balance Sheet Date [Member]
Unrecorded Unconditional Purchase Obligation [Line Items]
Guarantor Obligations, Maximum Exposure, Undiscounted	211,605
More Than Three And Within Five Years From Balance Sheet Date [Member]
Unrecorded Unconditional Purchase Obligation [Line Items]
Guarantor Obligations, Maximum Exposure, Undiscounted	0
Beyond Five Years of Balance Sheet Date [Member]
Unrecorded Unconditional Purchase Obligation [Line Items]
Guarantor Obligations, Maximum Exposure, Undiscounted	1
Standby Letters of Credit [Member]
Unrecorded Unconditional Purchase Obligation [Line Items]
Guarantor Obligations, Maximum Exposure, Undiscounted	329,898
Standby Letters of Credit [Member] | Balance on First Anniversary [Member]
Unrecorded Unconditional Purchase Obligation [Line Items]
Guarantor Obligations, Maximum Exposure, Undiscounted	160,678
Standby Letters of Credit [Member] | More Than One And Within Three Years From Balance Sheet Date [Member]
Unrecorded Unconditional Purchase Obligation [Line Items]
Guarantor Obligations, Maximum Exposure, Undiscounted	169,220
Standby Letters of Credit [Member] | More Than Three And Within Five Years From Balance Sheet Date [Member]
Unrecorded Unconditional Purchase Obligation [Line Items]
Guarantor Obligations, Maximum Exposure, Undiscounted	0
Standby Letters of Credit [Member] | Beyond Five Years of Balance Sheet Date [Member]
Unrecorded Unconditional Purchase Obligation [Line Items]
Guarantor Obligations, Maximum Exposure, Undiscounted	0
Surety Bonds [Member]
Unrecorded Unconditional Purchase Obligation [Line Items]
Guarantor Obligations, Maximum Exposure, Undiscounted	774,006
Surety Bonds [Member] | Balance on First Anniversary [Member]
Unrecorded Unconditional Purchase Obligation [Line Items]
Guarantor Obligations, Maximum Exposure, Undiscounted	731,620
Surety Bonds [Member] | More Than One And Within Three Years From Balance Sheet Date [Member]
Unrecorded Unconditional Purchase Obligation [Line Items]
Guarantor Obligations, Maximum Exposure, Undiscounted	42,385
Surety Bonds [Member] | More Than Three And Within Five Years From Balance Sheet Date [Member]
Unrecorded Unconditional Purchase Obligation [Line Items]
Guarantor Obligations, Maximum Exposure, Undiscounted	0
Surety Bonds [Member] | Beyond Five Years of Balance Sheet Date [Member]
Unrecorded Unconditional Purchase Obligation [Line Items]
Guarantor Obligations, Maximum Exposure, Undiscounted	1
Employee Related Commitments [Member] | Standby Letters of Credit [Member]
Unrecorded Unconditional Purchase Obligation [Line Items]
Guarantor Obligations, Maximum Exposure, Undiscounted	190,358
Employee Related Commitments [Member] | Standby Letters of Credit [Member] | Balance on First Anniversary [Member]
Unrecorded Unconditional Purchase Obligation [Line Items]
Guarantor Obligations, Maximum Exposure, Undiscounted	71,624
Employee Related Commitments [Member] | Standby Letters of Credit [Member] | More Than One And Within Three Years From Balance Sheet Date [Member]
Unrecorded Unconditional Purchase Obligation [Line Items]
Guarantor Obligations, Maximum Exposure, Undiscounted	118,734
Employee Related Commitments [Member] | Standby Letters of Credit [Member] | More Than Three And Within Five Years From Balance Sheet Date [Member]
Unrecorded Unconditional Purchase Obligation [Line Items]
Guarantor Obligations, Maximum Exposure, Undiscounted	0
Employee Related Commitments [Member] | Standby Letters of Credit [Member] | Beyond Five Years of Balance Sheet Date [Member]
Unrecorded Unconditional Purchase Obligation [Line Items]
Guarantor Obligations, Maximum Exposure, Undiscounted	0
Employee Related Commitments [Member] | Surety Bonds [Member]
Unrecorded Unconditional Purchase Obligation [Line Items]
Guarantor Obligations, Maximum Exposure, Undiscounted	204,884
Employee Related Commitments [Member] | Surety Bonds [Member] | Balance on First Anniversary [Member]
Unrecorded Unconditional Purchase Obligation [Line Items]
Guarantor Obligations, Maximum Exposure, Undiscounted	204,884
Employee Related Commitments [Member] | Surety Bonds [Member] | More Than One And Within Three Years From Balance Sheet Date [Member]
Unrecorded Unconditional Purchase Obligation [Line Items]
Guarantor Obligations, Maximum Exposure, Undiscounted	0
Employee Related Commitments [Member] | Surety Bonds [Member] | More Than Three And Within Five Years From Balance Sheet Date [Member]
Unrecorded Unconditional Purchase Obligation [Line Items]
Guarantor Obligations, Maximum Exposure, Undiscounted	0
Employee Related Commitments [Member] | Surety Bonds [Member] | Beyond Five Years of Balance Sheet Date [Member]
Unrecorded Unconditional Purchase Obligation [Line Items]
Guarantor Obligations, Maximum Exposure, Undiscounted	0
Environment Related Commitments [Member] | Standby Letters of Credit [Member]
Unrecorded Unconditional Purchase Obligation [Line Items]
Guarantor Obligations, Maximum Exposure, Undiscounted	56,294
Environment Related Commitments [Member] | Standby Letters of Credit [Member] | Balance on First Anniversary [Member]
Unrecorded Unconditional Purchase Obligation [Line Items]
Guarantor Obligations, Maximum Exposure, Undiscounted	54,566
Environment Related Commitments [Member] | Standby Letters of Credit [Member] | More Than One And Within Three Years From Balance Sheet Date [Member]
Unrecorded Unconditional Purchase Obligation [Line Items]
Guarantor Obligations, Maximum Exposure, Undiscounted	1,728
Environment Related Commitments [Member] | Standby Letters of Credit [Member] | More Than Three And Within Five Years From Balance Sheet Date [Member]
Unrecorded Unconditional Purchase Obligation [Line Items]
Guarantor Obligations, Maximum Exposure, Undiscounted	0
Environment Related Commitments [Member] | Standby Letters of Credit [Member] | Beyond Five Years of Balance Sheet Date [Member]
Unrecorded Unconditional Purchase Obligation [Line Items]
Guarantor Obligations, Maximum Exposure, Undiscounted	0
Environment Related Commitments [Member] | Surety Bonds [Member]
Unrecorded Unconditional Purchase Obligation [Line Items]
Guarantor Obligations, Maximum Exposure, Undiscounted	537,167
Environment Related Commitments [Member] | Surety Bonds [Member] | Balance on First Anniversary [Member]
Unrecorded Unconditional Purchase Obligation [Line Items]
Guarantor Obligations, Maximum Exposure, Undiscounted	495,017
Environment Related Commitments [Member] | Surety Bonds [Member] | More Than One And Within Three Years From Balance Sheet Date [Member]
Unrecorded Unconditional Purchase Obligation [Line Items]
Guarantor Obligations, Maximum Exposure, Undiscounted	42,150
Environment Related Commitments [Member] | Surety Bonds [Member] | More Than Three And Within Five Years From Balance Sheet Date [Member]
Unrecorded Unconditional Purchase Obligation [Line Items]
Guarantor Obligations, Maximum Exposure, Undiscounted	0
Environment Related Commitments [Member] | Surety Bonds [Member] | Beyond Five Years of Balance Sheet Date [Member]
Unrecorded Unconditional Purchase Obligation [Line Items]
Guarantor Obligations, Maximum Exposure, Undiscounted	0
Other Commitments [Member] | Standby Letters of Credit [Member]
Unrecorded Unconditional Purchase Obligation [Line Items]
Guarantor Obligations, Maximum Exposure, Undiscounted	83,246
Other Commitments [Member] | Standby Letters of Credit [Member] | Balance on First Anniversary [Member]
Unrecorded Unconditional Purchase Obligation [Line Items]
Guarantor Obligations, Maximum Exposure, Undiscounted	34,488
Other Commitments [Member] | Standby Letters of Credit [Member] | More Than One And Within Three Years From Balance Sheet Date [Member]
Unrecorded Unconditional Purchase Obligation [Line Items]
Guarantor Obligations, Maximum Exposure, Undiscounted	48,758
Other Commitments [Member] | Standby Letters of Credit [Member] | More Than Three And Within Five Years From Balance Sheet Date [Member]
Unrecorded Unconditional Purchase Obligation [Line Items]
Guarantor Obligations, Maximum Exposure, Undiscounted	0
Other Commitments [Member] | Standby Letters of Credit [Member] | Beyond Five Years of Balance Sheet Date [Member]
Unrecorded Unconditional Purchase Obligation [Line Items]
Guarantor Obligations, Maximum Exposure, Undiscounted	0
Other Commitments [Member] | Surety Bonds [Member]
Unrecorded Unconditional Purchase Obligation [Line Items]
Guarantor Obligations, Maximum Exposure, Undiscounted	31,955
Other Commitments [Member] | Surety Bonds [Member] | Balance on First Anniversary [Member]
Unrecorded Unconditional Purchase Obligation [Line Items]
Guarantor Obligations, Maximum Exposure, Undiscounted	31,719
Other Commitments [Member] | Surety Bonds [Member] | More Than One And Within Three Years From Balance Sheet Date [Member]
Unrecorded Unconditional Purchase Obligation [Line Items]
Guarantor Obligations, Maximum Exposure, Undiscounted	235
Other Commitments [Member] | Surety Bonds [Member] | More Than Three And Within Five Years From Balance Sheet Date [Member]
Unrecorded Unconditional Purchase Obligation [Line Items]
Guarantor Obligations, Maximum Exposure, Undiscounted	0
Other Commitments [Member] | Surety Bonds [Member] | Beyond Five Years of Balance Sheet Date [Member]
Unrecorded Unconditional Purchase Obligation [Line Items]
Guarantor Obligations, Maximum Exposure, Undiscounted	$ 1