Note 21. Net Income Per Share (Tables)

12 Months Ended

Dec. 31, 2015

Schedule of Earnings Per Share, Basic and Diluted [Table Text Block]

The calculation of basic and diluted net income per share for the years ended December 31, 2015, 2014, and 2013 was as follows (in thousands, except per share amounts):



	2015		2014		2013
Basic net income per share
Numerator:
Net income	$	546,421	$	395,964	$	350,718
Denominator:
Weighted-average common stock outstanding	100,886		100,048		93,697

Diluted net income per share
Denominator:
Weighted-average common stock outstanding	100,886		100,048		93,697
Effect of restricted and performance stock units and stock purchase plan shares	929		1,595		1,771
Weighted-average shares used in computing diluted net income per share	101,815		101,643		95,468



	2015		2014		2013
Per share information – basic:
Net income per share	$	5.42	$	3.96	$	3.74

Per share information – diluted:
Net income per share	$	5.37	$	3.90	$	3.67

Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share [Table Text Block]

The following table summarizes the potential shares of common stock that were excluded from the computation of diluted net income per share for the years ended December 31, 2015, 2014, and 2013 as they would have had an anti-dilutive effect (in thousands):

Anti-dilutive shares