XML 63 R32.htm IDEA: XBRL DOCUMENT v3.8.0.1
Summary of the Business and Significant Accounting Policies (Tables)
 12 Months Ended
Dec. 31, 2017
Accounting Policies [Abstract]  
Schedule of Average Rates Used Allocated Between Depreciation Expense and Construction Expense Projects Based on Use of Equipment
Average straight-line rates used were as follows:
 
Year ended December 31
 
2017
 
2016
 
2015
PNM
 
 
 
 
 
Electric plant
2.52
%
 
2.33
%
 
2.27
%
Common, intangible, and general plant
8.36
%
 
5.40
%
 
4.66
%
TNMP
3.57
%
 
3.66
%
 
3.65
%
Schedule of Inventory
Inventories consisted of the following at December 31:
 
PNMR
 
PNM
 
TNMP
 
2017
 
2016
 
2017
 
2016
 
2017
 
2016
 
(In thousands)
Coal
$
16,714

 
$
19,940

 
$
16,714

 
$
19,940

 
$
—

 
$
—

Materials and supplies
49,788

 
53,087

 
44,145

 
44,461

 
5,643

 
8,626

 
$
66,502

 
$
73,027

 
$
60,859

 
$
64,401

 
$
5,643

 
$
8,626