Summary of Significant Accounting Policies (Tables)

12 Months Ended

Dec. 31, 2017

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,
	2017	2016	2015
Cummins Inc.	13.4%	9.9%	9.3%
Honda Motor Co.	11.2%	10.7%	10.7%
Toyota Motor Corporation	10.2%	10.4%	10.1%

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

Costs of molds, dies and other tools used to make products sold for which we have a contractual guarantee for lump sum reimbursement from the customer are included in other current assets on the Consolidated Balance Sheets until reimbursement is received from the customer. A summary of amounts to be received from customers is as follows:

	December 31,
	2017		2016
Cost of molds, dies and other tools included in other current assets	$	3,382	$	2,837

Summary of customer reimbursement receivable

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. A summary of amounts received from customers is as follows:

	Years Ended December 31,
	2017		2016		2015
Reimbursements received from customers	$	4,299	$	2,036	$	1,861

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,
	2017		2016			2015
Foreign currency gains (losses)	$	3,052	$	(3,714	)	$	(6,299	)

Options

Summary of antidilutive stock options

Our antidilutive stock options and RSUs consist of the following:

	Years Ended December 31,
(units)	2017	2016	2015
Antidilutive stock options and RSUs	22,110	35,189	13,979