XML 73 R34.htm IDEA: XBRL DOCUMENT v3.10.0.1
Balance Sheet Components Balance Sheet Components (Policies)
 12 Months Ended
Dec. 31, 2018
Balance Sheet Components [Abstract]  
Allowance For Doubtful Accounts
Allowance for Doubtful Accounts
The Company maintains an allowance for doubtful accounts to provide for estimated and potential losses on accounts receivable. The Company determines the allowance for utility and other customer accounts receivable based on historical write-offs as compared to accounts receivable and operating revenues. Additionally, the Company establishes specific allowances for certain individual accounts. The following table presents the activity in the allowance for doubtful accounts during the years ended December 31 (dollars in thousands):
 
2018
 
2017
 
2016
Allowance as of the beginning of the year
$
5,132

 
$
5,026

 
$
4,530

Additions expensed during the year
3,917

 
5,317

 
6,053

Net deductions
(3,816
)
 
(5,211
)
 
(5,557
)
Allowance as of the end of the year
$
5,233

 
$
5,132

 
$
5,026
Inventory, Policy [Policy Text Block]
Inventories of materials and supplies, fuel stock and stored natural gas are recorded at average cost for our regulated operations and the lower of cost or market for our non-regulated operations and consisted of the following as of December 31 (dollars in thousands):
 
2018
 
2017
Materials and supplies
$
47,403

 
$
41,493

Fuel stock
4,869

 
4,843

Stored natural gas
11,609

 
11,739

Total
$
63,881

 
$
58,075