8. Equity

Common Stock

As of September 30, 2016, we had authorization to purchase a total of approximately 8.4 million shares under our existing share repurchase plan, or about 12% of outstanding shares. There were no share repurchases in the nine-month period ended September 30, 2016. Repurchased and subsequently retired shares are restored to the status of authorized but unissued shares.

Common stock and additional paid-in capital activity included the following:


	Three Months Ended					Nine Months Ended
	September 30, 2016					September 30, 2016
				Weighted Average					Weighted Average
	Shares	Amount		Exercise Price		Shares	Amount		Exercise Price
	(in millions, except share and per share amounts)
Stock-based compensation	37,240	$	5.9			187,402	$	16.1
Stock options exercised	22,125		1.2	$	52.80	636,870		31.3	$	49.14
Cumulative effect of change in accounting for stock-based compensation			—					1.0
Total	59,365	$	7.1			824,272	$	48.4

Dividends

On October 19, 2016, our Board of Directors declared the 2016 fourth quarter cash dividend of $0.425 per share. The dividend is payable on December 16, 2016 to stockholders of record as of November 18, 2016.

During the three months ended September 30, 2016 and 2015, we declared and paid a quarterly dividend of $0.425 per share and $0.40 per share, or $31.5 million and $29.3 million in total, respectively. During the nine months ended September 30, 2016 and 2015, we declared and paid quarterly dividends of $1.225 per share and $1.20 per share, or $88.6 million and $89.7 million in total, respectively. During the nine months ended September 30, 2016 and 2015, we paid $0.9 million and $1.0 million in dividend equivalents with respect to vested restricted stock units (“RSUs”), respectively.

Stock-Based Compensation

Effective January 1, 2016, we adopted accounting changes issued by the FASB for stock-based compensation that allow us to account for forfeitures of RSUs as they occur rather than estimating the number of forfeitures. As a result of the adoption, we recorded a cumulative-effect adjustment that reduced beginning retained earnings by $0.6 million, net of tax.

We make annual grants of long-term incentive awards to officers and key employees in the forms of service-based and performance-based RSUs that generally have 3-year vesting periods. The performance-based RSU awards are subject to both service and performance goal criteria. We also grant restricted stock to the non-employee members of the Board of Directors. The fair value of the RSUs and restricted stock awards is determined based on the closing stock price of our common stock on the grant date.

A summary of the status of our unvested restricted stock grants and service-based and performance-based RSUs as of September 30, 2016 and changes during the nine-month period then ended is as follows:


		Weighted
		Average Grant
Unvested Shares	Shares	Date Fair Value
Unvested at January 1, 2016	900,410	$	63.26
Granted(1)	524,746		69.20
Vested	(72,269)		56.25
Cancelled	(81,377)		68.12
Unvested at September 30, 2016	1,271,510	$	65.81
Shares reserved for future grants (all plans)	1,930,139

(1) 512,895 RSUs, including 190,175 performance-based RSUs, and 11,851 restricted stock grants.

Accumulated Other Comprehensive Loss

Accumulated other comprehensive loss included the following:


			Pension and		Accumulated
	Foreign Currency		Postretirement		Other
	Translation		Benefit Adjustments,		Comprehensive
	(Loss) Gain		Net of Tax		(Loss) Income
	(in millions)
Balance as of January 1, 2016	$	(74.2)	$	(25.5)	$	(99.7)
Current-period change		7.7		—		7.7
Balance as of September 30, 2016	$	(66.5)	$	(25.5)	$	(92.0)

Foreign currency translation adjustments are not generally adjusted for income taxes as they relate to indefinite investments in foreign subsidiaries. Pension and postretirement benefit adjustments are net of taxes of $15.6 million as of September 30, 2016 and December 31, 2015.