Shareholders' Equity

Common Stock and Debt Repurchase Authorizations

On July 21, 2016, the Board of Directors authorized the repurchase of up to $100 million of the company’s common stock and up to $150 million aggregate principal amount of any of the company’s debt securities (including convertible debt securities), in each case from time to time through open market purchases, privately negotiated transactions or otherwise, until September 30, 2019, subject to compliance with legal and regulatory requirements and the company's debt covenants. As of December 31, 2017, there was an insignificant amount of common stock and $100 million in debt security repurchases that were made under these authorizations.

Accumulated Other Comprehensive Loss (“AOCL”)

The components of AOCL and the changes in AOCL by components, net of tax, for three months ended December 31, 2017 and 2016 are as follows (in millions):



	Foreign Currency Translation			Employee Benefit Related Adjustments			Unrealized Loss, net of tax			Total
Balance at September 30, 2017	$	(41	)	$	(500	)	$	(4	)	$	(545	)
Other comprehensive income (loss) before reclassification	(8		)	1			—			(7		)
Amounts reclassified from accumulated other comprehensive loss	—			2			—			2
Net current-period other comprehensive income (loss)	$	(8	)	$	3		$	—		$	(5	)
Balance at December 31, 2017	$	(49	)	$	(497	)	$	(4	)	$	(550	)



Details about Accumulated Other Comprehensive Income Components	Amount Reclassified from Accumulated Other Comprehensive Income			Affected Line Item in the Consolidated Statement of Operations
Employee Benefit Related Adjustment
Prior service costs	$	(9	)	^(a)
Actuarial losses	$	11		^(a)
	2			Total before tax
	—			Tax benefit
Total reclassifications for the period	$	2		Net of tax
^(a) These accumulated other comprehensive income components are included in the computation of net periodic pension and retiree medical expense (see Note 20 for additional details), which is recorded in cost of sales and selling, general and administrative expenses.



	Foreign Currency Translation			Employee Benefit Related Adjustments			Unrealized Loss, net of tax			Total
Balance at September 30, 2016	$	(66	)	$	(740	)	$	(3	)	$	(809	)
Other comprehensive income (loss) before reclassification	(28		)	1			1			(26		)
Amounts reclassified from accumulated other comprehensive loss - net of tax	—			10			—			10
Net current-period other comprehensive income (loss)	$	(28	)	$	11		$	1		$	(16	)
Balance at December 31, 2016	$	(94	)	$	(729	)	$	(2	)	$	(825	)



Details about Accumulated Other Comprehensive Income Components	Amount Reclassified from Accumulated Other Comprehensive Income			Affected Line Item in the Consolidated Statement of Operations
Employee Benefit Related Adjustment
Prior service costs	$	(1	)	^(b)
Actuarial losses	11			^(b)
	10			Total before tax
	—			Tax expense
Total reclassifications for the period	$	10		Net of tax


^(b) These accumulated other comprehensive income components are included in the computation of net periodic pension and retiree medical expense (see Note 20 for additional details), which is recorded in cost of sales and selling, general and administrative expenses.