Summary of Significant Accounting Policies (Tables)

12 Months Ended

Dec. 31, 2019

Summary of Significant Accounting Policies

Schedule of the Company sales to major customers (purchases in excess of 10% of total sales)

	2017		2018		2019
Company A	4	%	8	%	16	%
Company B	14		6		15
Company C	20		13		9
Company D	—		14		3
All others	62		59		57
	100	%	100	%	100	%

Reconciliation of basic weighted average shares outstanding to diluted weighted average shares outstanding

The following is a reconciliation of the Company’s basic weighted average shares outstanding to diluted weighted average shares outstanding during the periods presented (in thousands):

	Year ended December 31,
	2017	2018	2019
Basic weighted average number of shares outstanding	315,426	316,036	306,400
Add: Dilutive effect of restricted stock units	817	—	—
Add: Dilutive effect of outstanding stock options	—	—	—
Add: Dilutive effect of performance stock units	40	—	—
Diluted weighted average number of shares outstanding	316,283	316,036	306,400
Weighted average number of outstanding equity awards excluded from calculation of diluted earnings per common share (1):
Restricted stock units	1,521	2,844	2,357
Outstanding stock options	676	626	527
Performance stock units	1,054	1,705	1,443

⁽¹⁾    The potential dilutive effects of these awards were excluded from the computation of earnings (loss) per common share—assuming dilution because the inclusion of these awards would have been anti-dilutive.