BENEFIT PLANS: Level 3 (Tables)

9 Months Ended

Sep. 30, 2016

Defined Benefit Pension Plans and Defined Benefit Postretirement Plans Disclosure [Abstract]

Schedule of Defined Benefit Plans Disclosures [Table Text Block]

The following table shows the components of net periodic benefit costs for the pension, SMSP, and postretirement benefits plans for the three months ended September 30, 2016 and 2015 (in thousands of dollars). 

	Pension Plan						SMSP				Postretirement Benefits
	2016			2015			2016		2015		2016			2015
Service cost	$	8,004		$	8,291		$	307	$	422	$	279		$	308
Interest cost	9,453			8,792			1,069		967		692			670
Expected return on plan assets	(10,519		)	(10,994		)	—		—		(619		)	(669		)
Amortization of prior service cost	15			56			42		47		7			3
Amortization of net loss	3,332			3,482			883		1,048		—			—
Net periodic benefit cost	10,285			9,627			2,301		2,484		359			312
Adjustments due to the effects of regulation(1)	(5,538		)	(4,902		)	—		—		—			—
Net periodic benefit cost recognized for financial reporting(1)	$	4,747		$	4,725		$	2,301	$	2,484	$	359		$	312

⁽¹⁾ Net periodic benefit costs for the pension plan are recognized for financial reporting based upon the authorization of each regulatory jurisdiction in which Idaho Power operates. Under IPUC order, income statement recognition of pension plan costs is deferred until costs are recovered through rates.

The table below shows the components of net periodic benefit costs for the pension, SMSP, and postretirement benefits plans for the nine months ended September 30, 2016 and 2015 (in thousands of dollars). 

	Pension Plan						SMSP				Postretirement Benefits
	2016			2015			2016		2015		2016			2015
Service cost	$	24,014		$	24,873		$	921	$	1,267	$	837		$	926
Interest cost	28,360			26,378			3,206		2,901		2,075			2,009
Expected return on plan assets	(31,560		)	(31,733		)	—		—		(1,856		)	(2,010		)
Amortization of prior service cost	44			166			126		139		20			11
Amortization of net loss	9,998			10,446			2,649		3,146		—			—
Net periodic benefit cost	30,856			30,130			6,902		7,453		1,076			936
Adjustments due to the effects of regulation(1)	(16,643		)	(15,873		)	—		—		—			—
Net periodic benefit cost recognized for financial reporting(1)	$	14,213		$	14,257		$	6,902	$	7,453	$	1,076		$	936

⁽¹⁾ Net periodic benefit costs for the pension plan are recognized for financial reporting based upon the authorization of each regulatory jurisdiction in which Idaho Power operates. Under IPUC order, income statement recognition of pension plan costs is deferred until costs are recovered through rates.