Equity Compensation Plans (Tables)

12 Months Ended

Dec. 31, 2017

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

Schedule of Share-based Payment Award, Stock Options, Valuation Assumptions

The fair value of each option granted was estimated on the date of grant using the Black-Scholes option-pricing model with the following weighted-average assumptions for the years ended December 31:

	2017		2016		2015
Risk-free interest rate	2.2	%	1.8	%	1.8	%
Expected life	5.5 years		5.5 years		5.5 years
Expected volatility	33	%	42	%	43	%
Expected dividend yield	—	%	—	%	—	%

Schedule of Nonvested Share Activity

The following is a summary of the option activity as of December 31, 2017 and changes during the year then ended:

In thousands except per share amounts and years
	Shares	Weighted-Average Exercise Price		Weighted- Average Remaining Contractual Term (years)	Aggregate Intrinsic Value
Outstanding at December 31, 2016	427	$	25.32
Granted	100	$	51.85
Exercised	(91)	$	14.87
Forfeited/Cancelled	(3)	$	64.20
Outstanding at December 31, 2017	433	$	33.37	7.1	$	8,116
Options exercisable at December 31, 2017	230	$	22.11	5.5	$	6,703
Unvested at December 31, 2017	203	$	46.05	8.1	$	1,413

Schedule of Nonvested Restricted Stock Units Activity

The following is a summary of the Company’s unvested restricted shares for the year ended and as of December 31, 2017:

In thousands except per share amounts
Outstanding Restricted Shares	Shares	Weighted-Average Grant-Date Fair Value
Nonvested at December 31, 2016	296	$	34.01
Granted	76	$	45.18
Vested	(139)	$	22.63
Forfeited/Cancelled	(14)	$	38.95
Nonvested December 31, 2017	219	$	44.77