The following financial information reflects all normal recurring adjustments, which are, in the opinion of management, necessary for a fair statement of the results of the interim periods. Summarized quarterly data for the years ended December 31, 2016 and 2015 are as follows (in thousands, except per share data).

2016 Quarters	First Quarter			Second Quarter			Third Quarter		Fourth Quarter
Revenue	$	36,874		$	38,470		$	110,927	$	160,349
Operating expenses	$	91,526		$	87,397		$	94,819	$	119,194
Income (loss) from operations	$	(54,652	)	$	(48,927	)	$	16,108	$	41,155
Net income (loss)	$	(62,917	)	$	(56,855	)	$	7,351	$	25,865
Basic net income (loss) per share (1)	$	(0.52	)	$	(0.47	)	$	0.06	$	0.21
Diluted net income (loss) per share (1) (2) (3)	$	(0.52	)	$	(0.47	)	$	0.06	$	0.21

2015 Quarters	First Quarter			Second Quarter		Third Quarter			Fourth Quarter
Revenue	$	62,583		$	120,428	$	49,121		$	51,571
Operating expenses	$	71,913		$	75,782	$	97,259		$	114,511
Income (loss) from operations	$	(9,330	)	$	44,646	$	(48,138	)	$	(62,940	)
Net income (loss)	$	(16,717	)	$	35,648	$	(35,776	)	$	(71,433	)
Basic net income (loss) per share (1)	$	(0.14	)	$	0.30	$	(0.30	)	$	(0.59	)
Diluted net income (loss) per share (1) (4)	$	(0.14	)	$	0.29	$	(0.30	)	$	(0.59	)

(1)	We computed net income (loss) per share independently for each of the quarters presented. Therefore, the sum of the quarterly net income (loss) per share will not necessarily equal the total for the year.

(2)

For the three months ended December 31, 2016, we had net income. As a result, we computed diluted net income per share using the weighted-average number of common shares and dilutive common equivalent shares outstanding during the period. Diluted common equivalent shares for the three months ended December 31, 2016 consisted of the following (in thousands):

Three Months Ended December 31, 2016	Income (Numerator)		Shares (Denominator)		Per-Share Amount

Income available to common shareholders	$	25,865		121,340	$	0.21
Effect of diluted securities:
Shares issuable upon exercise of stock options		—		2,189
Shares issuable upon restricted stock award issuance		—		403
Shares issuable related to our ESPP		—		21
Income available to common shareholders, plus assumed conversions	$	25,865		123,953	$	0.21

For the three months ended December 31, 2016, the calculation excludes the 1 percent and 2¾ percent notes because the effect on diluted earnings per share would be anti-dilutive.

(3)

For the three months ended September 30, 2016, we had net income. As a result, we computed diluted net income per share using the weighted-average number of common shares and dilutive common equivalent shares outstanding during the period. Diluted common equivalent shares for the three months ended September 30, 2016 consisted of the following (in thousands):

Three Months Ended September 30, 2016	Income (Numerator)		Shares (Denominator)		Per-Share Amount

Income available to common shareholders	$	7,351		120,989	$	0.06
Effect of diluted securities:
Shares issuable upon exercise of stock options		—		2,129
Shares issuable upon restricted stock award issuance		—		202
Shares issuable related to our ESPP		—		58
Income available to common shareholders, plus assumed conversions	$	7,351		123,378	$	0.06

For the three months ended September 30, 2016, the calculation excludes the 1 percent and 2¾ percent notes because the effect on diluted earnings per share would be anti-dilutive.

(4)

For the three months ended June 30, 2015, we had net income. As a result, we computed diluted net income per share using the weighted-average number of common shares and dilutive common equivalent shares outstanding during the period. Diluted common equivalent shares for the three months ended June 30, 2015 consisted of the following (in thousands):

Three Months Ended June 30, 2015	Income (Numerator)		Shares (Denominator)		Per-Share Amount

Income available to common shareholders	$	35,648		119,742	$	0.30
Effect of diluted securities:
Shares issuable upon exercise of stock options		—		3,974
Shares issuable upon restricted stock award issuance		—		376
Shares issuable related to our ESPP		—		4
Shares issuable related to our 2¾ percent notes		1,047		3,683
Income available to common shareholders, plus assumed conversions	$	36,695		127,779	$	0.29

For the three months ended June 30, 2015, the calculation excludes the 1 percent notes because the effect on diluted earnings per share was anti-dilutive.