Stock Compensation Plans (Tables)

12 Months Ended

Dec. 31, 2016

Disclosure of Compensation Related Costs, Share-based Payments [Abstract]

Summary of significant stock options granted

The fair value of stock option awards granted during 2016, 2015 and 2014 was estimated at the date of grant using a Black-Scholes option-pricing method with the following assumptions:

	2016			2015			2014
Weighted-average fair value per option (Pre-Spinoff for 2014)	$	6.49		$	11.67		$	23.09
Risk-free interest rate	1.22		%	1.58		%	1.64		%
Dividend yield	3.04		%	2.29		%	1.75		%
Expected stock volatility	34.12		%	36.53		%	50.96		%
Expected life - years	5			5			5

Summary of stock option activity

A summary of stock option award activity for the year ended December 31, 2016 is presented below:

	Number of Shares		Weighted-average Exercise Price		Weighted-average Remaining Contractual Term	Aggregate Intrinsic Value (millions)
Outstanding - beginning of year	3,279,868		$	35.60
Granted - new awards	733,580		27.75
Exercised	(152,720	)	26.89
Canceled or expired	(77,231	)	36.55
Outstanding - end of year	3,783,497		$	34.41	6 years	$	22.2
Options expected to vest	3,751,006		$	34.41	6 years	$	22.0
Options exercisable	2,370,847		$	34.38	5 years	$	13.6

Summary of restricted share activity

A summary of stock award activity, including restricted shares, deferred shares, performance-based restricted stock units and time-based restricted stock units that will settle in common shares, for the year ended December 31, 2016 is as follows:

	Number of Shares		Weighted-average Grant Date Fair Value
Outstanding - beginning of year	1,014,770		$	40.69
Granted - new awards	613,165		28.21
Vested	(188,383	)	41.48
Canceled or expired	(90,377	)	39.92
Outstanding - end of year	1,349,175		$	34.96