Summary of Significant Accounting Policies (Tables)

12 Months Ended

Dec. 31, 2018

Summary of net sales to significant customers as a percentage of total net sales

Our net sales to significant customers as a percentage of total net sales were as follows:

	Years Ended December 31,
	2018	2017	2016
Cummins Inc.	15.2%	13.4%	9.9%
Honda Motor Co.	10.5%	11.2%	10.7%
Toyota Motor Corporation	10.5%	10.2%	10.4%

We sell automotive parts to these three customers for certain vehicle platforms under purchase agreements that have no volume commitments and are subject to purchase orders issued from time to time.

No other customer accounted for 10% or more of total net sales during these periods.

Summary of Molds, Dies and Other Tools

We occasionally enter into agreements with our customers whereby we receive a contractual guarantee to be reimbursed the costs we incur to construct molds, dies, and other tools that are used to make many of the products we sell. The costs we incur are included in other current assets on the Consolidated Balance Sheets until reimbursement is received from the customer. Reimbursements received from customers are netted against such costs and included in our Consolidated Statements of Earnings if the amount received is in excess of the costs that we incur. The following is a summary of amounts to be received from customers as of December 31, 2018 and 2017:

	December 31,
	2018		2017
Cost of molds, dies and other tools included in other current assets	$	5,388	$	3,382

Summary of customer reimbursement receivable

The following is a summary of amounts received from customers for molds, dies, and other tools during the years ended December 31, 2018 and 2017:

	Years Ended December 31,
	2018		2017
Reimbursements received from customers	$	4,483	$	4,299

Fair Value Measurements, Recurring and Nonrecurring

We estimate the fair value of our financial instruments as follows:

Instrument	Method for determining fair value
Cash, cash equivalents, accounts receivable and accounts payable	Cost, approximates fair value due to the short-term nature of these instruments.
Revolving credit facility	The fair value of long-term debt approximates carrying value and was determined by valuing a similar hypothetical coupon bond and attributing that value to our credit facility.
Interest rate swaps and forward contracts	The fair value of our interest rate swaps and forward contracts are measured using a market approach which uses current industry information.

Summary of foreign currency gain (loss) recorded in the statement of operations

Foreign currency gains (losses) recorded in the Consolidated Statement of Earnings includes the following:

	Years Ended December 31,
	2018			2017		2016
Foreign currency (losses) gains	$	(2,619	)	$	3,052	$	(3,714	)

Options

Summary of antidilutive stock options

Our antidilutive stock options and RSUs consist of the following:

	Years Ended December 31,
(units)	2018	2017	2016
Antidilutive stock options and RSUs	18,138	22,110	35,189