Net Income Per Share (Tables)

12 Months Ended

Dec. 31, 2018

Reconciliation of Common Shares Used for Basic and Diluted Earnings Per Share

The following table provides a reconciliation of the common shares used for basic net income per share to the diluted shares used for diluted net income per share:



Year Ended December 31,	2018	2017	2016
Basic weighted average shares outstanding	45,665,883	45,367,932	45,212,414
Effect of potential dilutive shares⁽¹⁾:
Warrants	441,104	—	312,619
Stock options	—	—	447
Restricted stock units	77,572	—	116,105
Performance stock units ⁽²⁾	375,276	—	81,939
Diluted weighted average shares outstanding	46,559,835	45,367,932	45,723,524
Anti-dilutive shares excluded from the above reconciliation
Stock options	16,667	126,667	110,000
Warrants	—	4,053,670	—
Restricted stock units	—	68,654	—
Performance stock units ⁽²⁾	—	322,943	—


(1)	For the year ended December 31, 2017, Ambac has a net loss and accordingly excluded all potentially dilutive securities from the determination of diluted loss per share as their impact was anti-dilutive.

(2)

Performance stock units that are dilutive are reflected based on the performance metrics through the balance sheet date. Performance stock units that are anti-dilutive are reflected at their target issuance amounts. Vesting of these units is contingent upon meeting certain performance metrics. Although a portion of these performance metrics have been achieved as of the respective period end, it is possible that awards may no longer meet the metric at the end of the performance period.