Stock-Based Compensation (Tables)

6 Months Ended

Jun. 30, 2016

Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]

Compensation costs included in statement of income for all stock-based compensation arrangements

The compensation cost that has been included in the Consolidated Statements of Operations for all stock-based compensation arrangements was as follows: 

	Three Months Ended June 30,						Six Months Ended June 30,
(in thousands)	2016			2015			2016			2015
Sales, marketing and administrative expense	$	7,415		$	5,446		$	11,846		$	12,723
Research and development expense		397			373			406			632
Cost of goods sold		53			63			105			138
Stock-based compensation expense before taxes		7,865			5,882			12,357			13,493
Related income tax benefits		(3,146	)		(2,353	)		(4,943	)		(5,397	)
Stock-based compensation expense, net of taxes	$	4,719		$	3,529		$	7,414		$	8,096

Weighted average assumptions used to estimate fair value of stock options granted and stock purchase rights under ESPP

The weighted average assumptions used to estimate the fair value of stock purchase rights under the employee stock purchase plan (“ESPP”) are as follows:

	Three Months Ended June 30,						Six Months Ended June 30,
	2016			2015			2016			2015
ESPP
Volatility		31	%		42	%		31	%		43	%
Expected term (years)		0.5			1.3			0.6			1.3
Risk free interest rate		0.4	%		0.2	%		0.3	%		0.2	%
Expected dividend yield		—	%		—	%		—	%		—	%