Stock-Based Compensation Plans (Tables)

12 Months Ended

Dec. 31, 2016

Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]

Stock-Based Compensation Expense

Total stock-based compensation expense was as follows:

	Year Ended December 31,
		2016		2015		2014
	(In thousands)
Employee:
Restricted stock and performance shares	$	12,459	$	10,792	$	8,193
Stock options		1,143		826		676
		13,602		11,618		8,869
Non-employee directors:
Restricted stock		909		901		900
Total stock-based compensation	$	14,511	$	12,519	$	9,769

Assumptions Used for the Black-Scholes Option-Pricing Model to Determine the Per Share Weighted Average Fair Value for Options Granted

The following table represents the assumptions used for the Black-Scholes option-pricing model to determine the per share weighted-average fair value for options granted for the three years ended December 31, 2016:

	2016		2015		2014
Expected life (years)	6.0		7.0		5.0
Risk-free interest rate	1.9	%	1.9	%	1.7	%
Expected volatility	33.0	%	56.7	%	35.5	%
Expected dividend yield	1.0	%	1.1	%	1.0	%

Stock Option Activity

The following table reports stock option activity during the three years ended December 31, 2016 and the intrinsic value as of December 31, 2016:

				Weighted-		Remaining
	Number of			Average		Contractual
	Shares			Exercise Price ($)		Term		Intrinsic Value ($)
								(In thousands)
Outstanding at December 31, 2013		1,220,449		$	15.01
Granted		382			63.07
Canceled		(41,071	)		41.47
Exercised		(165,340	)		15.85
Outstanding at December 31, 2014		1,014,420			13.81
Granted		120,650			88.15
Canceled		—			—
Exercised		(196,034	)		11.60
Outstanding at December 31, 2015		939,036			23.83
Granted		112,988			102.40
Canceled		(874	)		101.77
Exercised		(195,410	)		12.35			$	21,929
Outstanding at December 31, 2016		855,740			36.80		2.8		94,235
Exercisable at December 31, 2016		623,076			14.98		2.2		82,208

Summary of Performance of Share Activity for Annual Awards

The following table reports performance share activity for annual awards for the three years ended December 31, 2016:

Performance year	2016		2015		2014
Share pay-out at plan		15,390		28,520		29,678
Actual share pay-out in following year		21,423		37,696		25,228
Weighted average fair value per share on grant date	$	101.77	$	70.60	$	63.07

Restricted Stock and Performance Share Activity

The following table reports restricted stock and performance share activity during the three years ended December 31, 2016:

				Weighted-Average
	Number of			Grant Date Fair
	Restricted Shares			Value
Outstanding at December 31, 2013		569,734		$	31.86
Granted		149,349
Performance share pay-out		46,340
Canceled		(43,185	)
Vested		(286,249	)
Outstanding at December 31, 2014		435,989		$	41.83
Granted		117,668
Performance share pay-out		117,647
Canceled		(3,845	)
Vested		(235,321	)
Outstanding at December 31, 2015		432,138		$	56.24
Granted		95,419
Performance share pay-out		61,936
Canceled		(12,786	)
Vested		(192,729	)
Outstanding at December 31, 2016		383,978		$	71.50