| Schedule of Accumulated Other Comprehensive Income (Loss) | 
The following table presents changes in the components of AOCI, net of taxes, for the six months ended June 30, 2021:    
 | 
 | 
 | 
 | 
 | 
 | 
 | 
 | 
 | 
 | 
 | 
 | 
 | 
 | 
 | 
 | 
 | 
 | 
 
 | 
Cash Flow Hedge | 
 | 
 Foreign Currency Items | 
 | 
Total | 
 
 | 
(in thousands) | 
 
| Balance at December 31, 2020 | 
$ | 
(31,587) | 
 | 
 | 
$ | 
(145,422) | 
 | 
 | 
$ | 
(177,009) | 
 | 
 
Other comprehensive income before reclassifications  | 
9,308  | 
 | 
 | 
2,007  | 
 | 
 | 
11,315  | 
 | 
 
| Amount reclassified from AOCI | 
3,862  | 
 | 
 | 
—  | 
 | 
 | 
3,862  | 
 | 
 
| Net other comprehensive income | 
13,170  | 
 | 
 | 
2,007  | 
 | 
 | 
15,177  | 
 | 
 
| Balance at June 30, 2021 | 
$ | 
(18,417) | 
 | 
 | 
$ | 
(143,415) | 
 | 
 | 
$ | 
(161,832) | 
 | 
 
 
 | 
| Potentially Dilutive Securities Excluded From Diluted Net Income (Loss) Per Common Share | 
The following table shows securities excluded from the calculation of diluted net loss per common share because such securities are anti-dilutive:
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 | 
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 | 
 | 
 | 
 | 
 | 
 | 
 | 
 | 
 | 
 
 | 
Three Months Ended June 30, | 
 | 
Six Months Ended June 30, | 
 
 | 
2021 | 
 | 
2020 | 
 | 
2021 | 
 | 
2020 | 
 
| Options to purchase shares of common stock | 
7,797,075  | 
 | 
 | 
10,197,507  | 
 | 
 | 
7,797,075  | 
 | 
 | 
10,197,507  | 
 | 
 
| Restricted stock and deferred stock—unvested | 
3,007,032  | 
 | 
 | 
5,150,289  | 
 | 
 | 
3,007,032  | 
 | 
 | 
5,150,289  | 
 | 
 
 | 
 | 
 | 
 | 
 | 
 | 
 | 
 | 
 
| Conversion shares related to the convertible senior notes | 
11,864,035  | 
 | 
 | 
11,864,035  | 
 | 
 | 
11,864,035  | 
 | 
 | 
11,864,035  | 
 | 
 
| Number of anti-dilutive potentially issuable shares excluded from diluted common shares outstanding | 
22,668,142  | 
 | 
 | 
27,211,831  | 
 | 
 | 
22,668,142  | 
 | 
 | 
27,211,831  | 
 | 
 
 
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