Common Stock (Tables)

6 Months Ended

Jun. 30, 2018

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

Stock Options Status and Activity

Stock Options — The following table reflects the status and activity for all options to purchase common stock for the period indicated:

	Six Months Ended June 30, 2018
	Shares Under Option		Weighted Avg. Exercise Prices		Weighted Avg. Remaining Life in Years	Aggregate Intrinsic Value
						(Millions)
Outstanding Stock Options
Outstanding, January 1, 2018	318,016		$	43.60	2.6	$	5
Exercised	(4,607	)	26.78			—
Outstanding, March 31, 2018	313,409		43.84		2.1	4
Forfeited	(2,368	)	54.34			—
Outstanding, June 30, 2018	311,041		$	43.76	1.8	$	2

Nonvested Restricted Shares

Restricted Stock — The following table reflects the status for all nonvested restricted shares for the period indicated:

	Six Months Ended June 30, 2018
	Shares		Weighted Avg. Grant Date Fair Value
Nonvested Restricted Shares
Nonvested balance at January 1, 2018	410,251		$	49.95
Granted	17,440		55.05
Vested	(168,409	)	47.08
Forfeited	(5,108	)	48.68
Nonvested balance at March 31, 2018	254,174		52.23
Granted	1,573		47.97
Vested	(60,434	)	49.89
Forfeited	(2,482	)	57.15
Nonvested balance at June 30, 2018	192,831		$	53.14