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INVENTORIES
9 Months Ended
Sep. 30, 2014
Inventory Disclosure [Abstract]  
INVENTORIES
Inventories

PGL and NSG price natural gas storage injections at the calendar year average of the costs of natural gas supply purchased. Withdrawals from storage are priced on the Last-in, First-out (LIFO) cost method. For interim periods, the difference between current projected replacement cost and the LIFO cost for quantities of natural gas temporarily withdrawn from storage is recorded as a temporary LIFO liquidation debit or credit. At September 30, 2014, all LIFO layers were replenished, and the LIFO liquidation balance was zero.