The Company records net sales when performance obligations with our customer are satisfied. A performance obligation is a promise to transfer a distinct good to the customer and is the unit of account. The transaction price is allocated to each distinct performance obligation and recognized as net sales when, or as, the performance obligation is satisfied. All contracts have a single performance obligation as the promise to transfer the individual good is not separately identifiable from other promises and is, therefore, not distinct. Performance obligations are satisfied at a point in time and net sales are recognized when the customer accepts the delivery of a product or takes possession of a product with rights and rewards of ownership.

The Company enters into agreements with customers to offer rebates, generally based on achievement of specified sales levels and various marketing allowances that are common industry practice. Reductions to net sales for customer programs and incentive offerings, including promotions and other volume-based incentives, are estimated using the most likely amount method and recorded in the period in which the sale occurs. Provisions for early payment discounts are accrued in the same period in which the sale occurs. The Company does not have any material payment terms as payment is received shortly after the transfer of control of the products to the customer. Commissions to internal sales teams are paid to obtain contracts. As these contracts are less than one year, these costs are expensed as incurred.

The Company includes shipping and handling costs billed to customers in net sales. Related costs are accounted for as fulfillment activities and are recognized as cost of products sold when control of the products transfers to the customer.

The following table presents the Company’s net sales by product line and geography for the three and six months ended March 31, 2019 (in thousands):

	Three Months Ended March 31, 2019						Six Months Ended March 31, 2019
	U.S.		Canada		Total		U.S.		Canada		Total
Residential roofing products	$	594,525	$	4,392	$	598,917	$	1,308,021	$	15,759	$	1,323,780
Non-residential roofing products		296,156		17,470		313,626		682,833		47,106		729,939
Complementary building products		515,721		773		516,494		1,094,443		2,551		1,096,994
Total net sales	$	1,406,402	$	22,635	$	1,429,037	$	3,085,297	$	65,416	$	3,150,713