Share-Based Compensation (Tables)

12 Months Ended

Dec. 31, 2017

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

Summary of Stock Option Activity

A summary of stock option activity for 2017 is presented below:

	2017
	Number of Shares		Weighted Average Exercise Price		Weighted Average Remaining Contractual Term	Aggregate Intrinsic Value
	(in whole shares)					(in millions)
Outstanding — beginning of year	38,000		$	19.30
Granted	—		—
Exercised	(38,000	)	19.30
Canceled or expired	—		—
Outstanding — end of year	—		$	—	0.0	$	—
Options exercisable	—		$	—	0.0	$	—

Summary of Restricted Share Activity

A summary of restricted share and performance share activity for the year ended December 31, 2017 is as follows:

	2017
	Time-Based				Performance-Based
	Number of Shares		Weighted Average Grant Date Fair Value		Number of Shares		Weighted Average Grant Date Fair Value
	(in whole shares)				(in whole shares)
Outstanding — beginning of year	216,916		$	36.94	165,000		$	34.78
Granted(a)	105,670		38.48		165,000		38.10
Vested	(87,727	)	44.78		(55,000	)	34.78
Performance- to time-based(b)	110,000		34.78		(110,000	)	34.78
Canceled or expired	(2,000	)	37.87		—		—
Outstanding — end of year	342,859		$	34.71	165,000		$	38.10

(a) Included in the granted amount are 4,390 restricted share units.

(b) During the second quarter of 2017, 55,000 of the performance-based restricted shares granted in 2016 fully vested based on achievement of the performance criteria. In accordance with the grant agreements, the remaining 110,000 shares became time-based, vesting over the remaining two years of the requisite service period.