Stock-Based Compensation (Tables)

6 Months Ended

Jun. 30, 2018

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

Stock-Based Compensation Expense for Options Granted, Restricted Stock and Stock Purchase Rights as Reflected in Statement of Operations

Stock-based compensation expense for options granted, RSAs, performance stock awards (“PSAs”), SARs and stock purchase rights is reflected in the condensed consolidated statements of operations and comprehensive loss as follows:

	THREE MONTHS ENDED   JUNE 30,				SIX MONTHS ENDED   JUNE 30,
(in thousands)	2018		2017		2018		2017
Selling, general and administrative	$	7,760	$	5,251	$	14,444	$	9,037
Research and development	2,558		1,414		4,593		2,478
Total	$	10,318	$	6,665	$	19,037	$	11,515

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, 2017	6,457,343		$	22.15
Granted	1,047,134		56.05
Exercised	(363,559	)	10.68
Canceled	(94,573	)	44.35
Options outstanding at June 30, 2018	7,046,345		$	27.46	7.1	$	282,490
Options exercisable at June 30, 2018	4,403,259		$	16.41	6.0	$	225,165

Restricted Stock and Restricted Stock Units Activity

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

	NUMBER OF SHARES		WEIGHTED AVERAGE FAIR VALUE PER SHARE
Nonvested RSAs at December 31, 2017	447,049		$	41.08
Granted	254,216		55.92
Vested	(114,335	)	37.15
Canceled	(5,328	)	48.21
Nonvested RSAs at June 30, 2018	581,602		$	48.27