Equity-Based Compensation (Tables)

12 Months Ended

Dec. 31, 2015

Summary of details regarding stock options granted under equity incentive plans

	December 31, 2015
				Weighted
				Average
				Remaining	Aggregate Intrinsic
		Weighted Average		Contractual	Value ($ in
	Options	Exercise Price		Term	millions)
Outstanding at beginning of year	2,996,383	$	22.60	—	$	—
Granted	1,215,675		55.72	—		—
Exercised	(836,450)		21.58	—		—
Expired and/or forfeited	(471,431)		33.66	—		—
Outstanding at end of year	2,904,177	$	34.97	7.8	$	17,114
Outstanding at end of year - vested and unvested expected to vest	2,632,232	$	34.40	7.8	$	16,039
Exercisable at end of year	948,034	$	23.44	6.1	$	9,402

Summary of details regarding restricted stock units granted under equity incentive plans

	December 31, 2015
		Weighted Average
	Restricted	Grant Date
	Stock Units	Fair Value
Outstanding at beginning of year	541,226	$	20.62
Granted	411,429		52.71
Vested	(149,572)		23.56
Forfeited	(148,728)		34.78
Outstanding at end of year	654,355	$	36.90
Outstanding at end of year and expected to vest	567,954	$	36.85

Schedule of equity-based compensation expense

Equity‑based compensation expense for 2015, 2014 and 2013 consisted of the following (in thousands): 

	Years Ended December 31,
	2015		2014		2013
Cost of product sales	$	371	$	122	$	121
Research and development		2,992		1,596		2,149
Selling, general and administrative		13,874		6,907		5,734
Total equity-based compensation expense	$	17,237	$	8,625	$	8,004
Income tax effect		(4,885)		—		—
After-tax effect of equity-based compensation expense	$	12,352	$	8,625	$	8,004

Summary of weighted average assumptions used for valuing option awards granted

	Years Ended December 31,
	2015		2014		2013
		Non-Employee		Non-Employee		Non-Employee
	Employees	Directors	Employees	Directors	Employees	Directors
Risk free interest rate (%)	1.55	1.24	1.56	1.28	0.95	0.85
Expected volatility (%)	47	46	47	46	59	46
Expected option term (years)	5.00	4.00	5.00	4.00	5.00	4.00
Dividend yield	none	none	none	none	none	none

Equity Compensation Plans

Summary of details regarding stock options granted under equity incentive plans

	2007 Equity	2000 Equity	2013 Lumara
	Plan	Plan	Equity Plan	Total
Outstanding at December 31, 2014	2,051,017	35,266	44,000	2,130,283
Granted	919,675	—	76,000	995,675
Exercised	(657,724)	(21,226)	—	(678,950)
Expired or terminated	(349,806)	—	(24,000)	(373,806)
Outstanding at December 31, 2015	1,963,162	14,040	96,000	2,073,202

Summary of details regarding restricted stock units granted under equity incentive plans

	2007 Equity	2000 Equity	2013 Lumara
	Plan	Plan	Equity Plan	Total
Outstanding at December 31, 2014	360,826	—	20,000	380,826
Granted	268,954	—	60,225	329,179
Vested	(73,432)	—	(11,666)	(85,098)
Expired or terminated	(110,018)	—	(16,209)	(126,227)
Outstanding at December 31, 2015	446,330	—	52,350	498,680