Stock-based Compensation (Tables)

12 Months Ended

Dec. 31, 2019

Share-based Payment Arrangement [Abstract]

Schedule of Stock-Based Compensation Expense

Stock-based compensation expense for options granted, RSAs, PSAs, RSUs, SARs and stock purchase rights are reflected in the consolidated statements of operations and comprehensive loss as follows:

	YEAR ENDED DECEMBER 31,
(in thousands)	2019		2018		2017
Selling, general and administrative	$	30,463	$	26,432	$	18,613
Pre-approval commercial manufacturing	3,634		2,622		1,359
Research and development	10,996		9,674		6,106
Total	$	45,093	$	38,728	$	26,078

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

Weighted average assumptions utilized in the fair value calculation for options to purchase common stock as of December 31, 2019, 2018 and 2017 are as follows: 

	YEAR ENDED DECEMBER 31,
	2019		2018		2017
Expected term (years)	6.0		6.0		6.0
Expected stock price volatility	74	%	78	%	84	%
Risk-free interest rate	1.9	%	2.7	%	2.0	%
Dividend yield	—	%	—	%	—	%

Schedule of Stock Options Activity

The following table summarizes the stock option activity under the Plans:

	NUMBER OF SHARES		WEIGHTED AVERAGE EXERCISE PRICE		WEIGHTED AVERAGE REMAINING CONTRACTUAL LIFE (YEARS)	AGGREGATE INTRINSIC VALUE (000’s)
Options outstanding at December 31, 2018	6,935,119		$	28.96
Granted	2,252,643		31.37
Exercised	(287,148	)	16.29
Canceled	(474,572	)	46.45
Expired	(491	)	0.41
Options outstanding at December 31, 2019	8,425,551		$	29.06	6.7	$	42,107
Options exercisable at December 31, 2019	5,469,307		$	24.23	5.5	$	40,598

Schedule of Stock Options Outstanding and Exercisable Option Plans

The following table provides additional information about stock options that are outstanding and exercisable at December 31, 2019:

EXERCISE PRICE	OPTIONS OUTSTANDING	WEIGHTED AVERAGE REMAINING CONTRACTUAL LIFE (YEARS)	OPTIONS EXERCISABLE
$0.20 - $10.00	1,454,195	3.5	1,454,195
$10.01 - $20.00	1,067,692	6.5	855,530
$20.01 - $30.00	2,597,369	6.8	1,558,247
$30.01 - $45.00	1,283,424	7.7	698,592
$45.01 - $55.00	1,233,270	8.3	513,798
$55.01 - $73.10	789,601	8.2	388,945
	8,425,551		5,469,307

Schedule of Share-based Compensation, Restricted Stock and Restricted Stock Units Activity

The following table summarizes the RSA, including PSAs, activity under the Plans: 

	NUMBER OF SHARES		WEIGHTED AVERAGE FAIR VALUE PER SHARE
Nonvested RSAs at December 31, 2018	572,706		$	48.18
Granted	519,167		40.07
Vested	(214,276	)	45.76
Canceled	(123,182	)	49.64
Nonvested RSAs at December 31, 2019	754,415		$	43.07

Schedule of Stock Appreciation Rights

The following table summarizes the SARs activity under the Plans:

	NUMBER OF SHARES		WEIGHTED AVERAGE EXERCISE PRICE		WEIGHTED AVERAGE REMAINING CONTRACTUAL LIFE (YEARS)	AGGREGATE INTRINSIC VALUE (000’s)
SARs outstanding at December 31, 2018	91,000		$	53.75
Granted	113,851		33.73
Exercised	—		—
Canceled	(41,835	)	46.21
SARs outstanding at December 31, 2019	163,016		$	41.70	3.9	$	25
SARs exercisable at December 31, 2019	18,000		$	53.68	3.3	$	—