XML 41 R22.htm IDEA: XBRL DOCUMENT v2.4.1.9
SHORT-TERM INVESTMENTS: (Tables)
 3 Months Ended
Mar. 31, 2015
SHORT-TERM INVESTMENTS:  
Schedule of short-term investments

 

Short-term investments were as follows ($ in millions):

 

 

 

At March 31,

 

At December 31,

 

 

 

2015

 

2014

 

Trading securities

 

$
79.1 

 

$
333.7 

 

Weighted average interest rate

 
1.16 

%
0.78 

%

 

 

 

 

 

 

Available-for-sale

 

$
4.7 

 

$
4.9 

 

Weighted average interest rate

 
0.46 

%
0.44 

%

Total

 

$
83.8 

 

$
338.6 

 

 

Summary of activities in short-term investments

 

The following table summarizes the activity of these investments by category (in millions):

 

 

 

Three months ended
March 31,

 

 

 

2015

 

2014

 

Trading:

 

 

 

 

 

Interest earned

 

$
0.3 

 

$
1.4 

 

Unrealized gain (loss) at the end of the period

 

$
2.8 

 

$
2.2 

 

 

 

 

 

 

 

Available-for-sale:

 

 

 

 

 

Interest earned

 

(*)

 

(*)

 

Investment redeemed

 

$
0.2 

 

$

—

 

 

 

(*) Less than $0.1 million.