Annual report pursuant to Section 13 and 15(d)

Benefit Plans - Stock Options Activity under Share-Based Payment Plans (Details)

v3.3.1.900
Benefit Plans - Stock Options Activity under Share-Based Payment Plans (Details) - Employees And Non Employee Stock Option [Member] - USD ($)
$ / shares in Units, shares in Thousands, $ in Thousands
 12 Months Ended
Dec. 31, 2015
Dec. 31, 2014
Dec. 31, 2013
Options      
Outstanding, options, beginning balance (in shares) 267,854 264,239 274,512
Granted, options (in shares) 145,366 61,852 57,228
Exercised, options (in shares) (57,667) (46,943) (61,056)
Forfeited, cancelled or expired, options (in shares) (17,072) (11,294) (6,445)
Outstanding, options, ending balance (in shares) 338,481 267,854 264,239
Exercisable, options (in shares) 121,751    
Weighted- Average Exercise Price      
Outstanding, weighted-average exercise price, beginning balance (in dollars per share) $ 2.72 $ 2.42 $ 1.92
Granted, weighted-average exercise price (in dollars per share) 3.95 3.39 3.59
Exercised, weighted-average exercise price (in dollars per share) 1.88 1.63 1.31
Forfeited, cancelled or expired, weighted-average exercise price (in dollars per share) 4.60 4.08 2.02
Outstanding, weighted-average exercise price, ending balance (in dollars per share) 3.29 $ 2.72 $ 2.42
Exercisable, weighted-average exercise price (in dollars per share) $ 2.51    
Outstanding, weighted average remaining contractual term 7 years 5 months 27 days    
Exercisable, weighted average remaining contractual term 5 years 6 months    
Outstanding, aggregate intrinsic value $ 267,813    
Exercisable, aggregate intrinsic value $ 194,362