Benefit Plans (Tables)

12 Months Ended

Aug. 31, 2016

Compensation and Retirement Disclosure [Abstract]

Schedule of defined benefit plans disclosures

Financial information on changes in benefit obligation, plan assets funded and balance sheets status as of August 31, 2016 and 2015 is as follows:



	Qualified Pension Benefits						Non-Qualified Pension Benefits						Other Benefits
	2016			2015			2016			2015			2016			2015
	(Dollars in thousands)
Change in benefit obligation:
Benefit obligation at beginning of period	$	730,795		$	720,893		$	33,184		$	37,983		$	41,997		$	44,318
Service cost	37,533			36,006			1,035			875			1,412			1,513
Interest cost	30,773			28,046			1,406			1,414			1,709			1,489
Actuarial (gain) loss	361			20,993			(3,333		)	393			(4,892		)	1,563
Assumption change	57,385			(16,297		)	2,679			(1,082		)	2,602			(5,136		)
Plan amendments	411			—			(1,045		)	—			(4,495		)	—
Settlements	—			—			—			(5,715		)	—			—
Benefits paid	(44,509		)	(58,846		)	(1,230		)	(684		)	(1,554		)	(1,750		)
Benefit obligation at end of period	$	812,749		$	730,795		$	32,696		$	33,184		$	36,779		$	41,997
Change in plan assets:
Fair value of plan assets at beginning of period	$	796,379		$	822,125		$	—		$	—		$	—		$	—
Actual gain (loss) on plan assets	88,089			(6,065		)	—			—			—			—
Company contributions	43,306			39,165			1,230			6,399			1,554			1,750
Settlements	—			—			—			(5,715		)	—			—
Benefits paid	(44,509		)	(58,846		)	(1,230		)	(684		)	(1,554		)	(1,750		)
Fair value of plan assets at end of period	$	883,265		$	796,379		$	—		$	—		$	—		$	—
Funded status at end of period	$	70,516		$	65,584		$	(32,696	)	$	(33,184	)	$	(36,779	)	$	(41,997	)
Amounts recognized on balance sheet:
Non-current assets	$	70,594		$	65,927		$	—		$	—		$	—		$	—
Accrued benefit cost:
Current liabilities	—			—			(1,880		)	(1,752		)	(2,490		)	(2,708		)
Non-current liabilities	(78		)	(343		)	(30,816		)	(31,432		)	(34,289		)	(39,289		)
Ending balance	$	70,516		$	65,584		$	(32,696	)	$	(33,184	)	$	(36,779	)	$	(41,997	)
Amounts recognized in accumulated other comprehensive loss (pretax):
Prior service cost (credit)	$	4,021		$	5,217		$	(641	)	$	631		$	(4,847	)	$	(472	)
Net (gain) loss	275,146			276,450			7,815			9,161			(12,235		)	(10,409		)
Ending balance	$	279,167		$	281,667		$	7,174		$	9,792		$	(17,082	)	$	(10,881	)

Schedule of net benefit costs of assumptions used

Components of net periodic benefit costs for the years ended August 31, 2016, 2015 and 2014 are as follows:



	Qualified Pension Benefits									Non-Qualified Pension Benefits									Other Benefits
	2016			2015			2014			2016			2015			2014			2016			2015			2014
	(Dollars in thousands)
Components of net periodic benefit costs:
Service cost	$	37,533		$	36,006		$	30,417		$	1,035		$	875		$	860		$	1,412		$	1,513		$	1,729
Interest cost	30,773			28,046			29,900			1,406			1,414			1,660			1,709			1,489			1,918
Expected return on assets	(48,055		)	(49,746		)	(47,655		)	—			—			—			—			—			—
Settlement of retiree obligations	—			—			—			—			1,635			—			—			—			—
Prior service cost (credit) amortization	1,606			1,631			1,593			228			228			229			(120		)	(426		)	(493		)
Actuarial loss amortization	19,016			19,621			18,228			692			1,058			957			(464		)	(431		)	(180		)
Net periodic benefit cost	$	40,873		$	35,558		$	32,483		$	3,361		$	5,210		$	3,706		$	2,537		$	2,145		$	2,974
Weighted-average assumptions to determine the net periodic benefit cost:
Discount rate	4.20		%	4.00		%	4.80		%	4.20		%	4.00		%	4.50		%	4.20		%	4.20		%	3.75		%
Expected return on plan assets	6.00		%	6.50		%	6.75		%	N/A			N/A			N/A			N/A			N/A			N/A
Rate of compensation increase	4.90		%	4.90		%	4.85		%	4.90		%	5.15		%	4.75		%	N/A			N/A			N/A
Weighted-average assumptions to determine the benefit obligations:
Discount rate	3.60		%	4.20		%	4.00		%	3.30		%	4.50		%	4.50		%	3.30		%	3.75		%	4.60		%
Rate of compensation increase	5.60		%	4.90		%	4.90		%	5.60		%	4.80		%	4.80		%	N/A			N/A			N/A

Schedule of amounts in accumulated other comprehensive income (loss) to be recognized over next fiscal year

The estimated amortization in fiscal 2017 from accumulated other comprehensive loss into net periodic benefit cost is as follows:



	Qualified Pension Benefits		Non-Qualified Pension Benefits		Other Benefits
	(Dollars in thousands)
Amortization of prior service cost (benefit)	$	1,563	$	19	$	(565	)
Amortization of net actuarial (gain) loss	26,969		546		(913		)

Schedule of effect of one-percentage-point change in assumed health care cost trend rates

A one-percentage point change in the assumed health care cost trend rates would have the following effects:



	1% Increase		1% Decrease
	(Dollars in thousands)
Effect on total of service and interest cost components	$	280	$	(240	)
Effect on postretirement benefit obligation	2,700		(2,300		)

Schedule of expected benefit payments

retiree benefit payments, which reflect expected future service, are anticipated to be paid as follows:



	Qualified Pension Benefits		Non-Qualified Pension Benefits		Other Benefits
	Qualified Pension Benefits		Non-Qualified Pension Benefits		Gross
	(Dollars in thousands)
2017	$	48,399	$	1,880	$	2,490
2018	62,579		2,360		2,560
2019	68,104		2,360		2,670
2020	67,913		2,350		2,760
2021	71,891		2,540		2,850
2022-2026	400,300		16,370		14,690

Schedule of defined benefit plans, fair value disclosure

pension plans’ recurring fair value measurements by asset category at August 31, 2016 and 2015 are presented in the tables below:



	2016
	Level 1		Level 2		Level 3		Total
	(Dollars in thousands)
Cash and cash equivalents	$	4,841	$	—	$	—	$	4,841
Equities:
Mutual funds	507		—		—		507
Common/collective trust at net asset value ⁽¹⁾	—		—		—		228,717
Fixed income securities:
Common/collective trust at net asset value ⁽¹⁾	—		—		—		551,604
Partnership and joint venture interests measured at net asset value ⁽¹⁾	—		—		—		95,744
Other assets measured at net asset value ⁽¹⁾	—		—		—		1,852
Total	$	5,348	$	—	$	—	$	883,265



	2015
	Level 1		Level 2		Level 3		Total
	(Dollars in thousands)
Cash and cash equivalents	$	4,882	$	—	$	—	$	4,882
Equities:
Mutual funds	91,619		—		—		91,619
Common/collective trust at net asset value ⁽¹⁾	—		—		—		194,463
Fixed income securities:
Mutual funds	133,556		20,560		—		154,116
Common/collective trust at net asset value ⁽¹⁾	—		—		—		296,684
Partnership and joint venture interests measured at net asset value ⁽¹⁾	—		—		—		52,640
Other assets measured at net asset value ⁽¹⁾	—		—		—		1,975
Total	$	230,057	$	20,560	$	—	$	796,379

Schedule of multiemployer plans

participation in the Co-op Plan for the years ended August 31, 2016, 2015, and 2014 is outlined in the table below:



		Contributions of CHS
		(Dollars in thousands)
Plan Name	EIN/Plan Number	2016		2015		2014		Surcharge Imposed	Expiration Date of Collective Bargaining Agreement
Co-op Retirement Plan	01-0689331 / 001	$	1,862	$	2,021	$	2,079	N/A	N/A