The Company has two reporting segments, which consist of Global Spine and Global Extremities. Within the Global Spine reporting segment there are three product categories: Bone Growth Therapies, Spinal Implants and Biologics.

The table below presents net sales by major product category by reporting segment:

	Three Months Ended March 31,
(U.S. Dollars, in thousands)	2020		2019		Change
Bone Growth Therapies	$	45,443	$	47,283		-3.9	%
Spinal Implants		22,926		22,903		0.1	%
Biologics		13,949		15,732		-11.3	%
Global Spine		82,318		85,918		-4.2	%
Global Extremities		22,505		23,194		-3.0	%
Net sales	$	104,823	$	109,112		-3.9	%

The table below presents product sales and marketing service fees, which are both components of net sales:

Product sales primarily consist of the sale of bone growth therapies devices and internal and external fixation products. Marketing service fees are received from MTF Biologics based on total sales of biologics tissues and relate solely to the Global Spine reporting segment. Revenues exclude any value added or other local taxes, intercompany sales and trade discounts. Shipping and handling costs for products shipped to customers are included in cost of sales.

As discussed in Note 2, the Company adopted ASU No. 2016-13 - Financial Instruments—Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments and subsequent amendments, using the modified retrospective approach. Adoption of the new standard resulted in an increase to the Company’s allowance for expected credit losses of $1.1 million, an increase in deferred income tax assets of $0.2 million, and a decrease in retained earnings of $0.9 million as of January 1, 2020. The net impact of adoption to the Company’s balance sheet as of January 1, 2020 is presented in the table below. The standard did not have a material impact to the Company’s condensed consolidated statements of income or cash flows.

(U.S. Dollars, in thousands)	December 31, 2019			Impact of Adoption of ASC 326			January 1, 2020
Assets
Current assets
Cash, cash equivalents, and restricted cash	$	70,403		$	—		$	70,403
Accounts receivable, net		86,805			(1,120	)		85,685
Inventories		82,397			—			82,397
Prepaid expenses and other current assets		20,948			—			20,948
Total current assets		260,553			(1,120	)		259,433
Deferred income taxes		35,117			233			35,350
Other long-term assets		199,950			—			199,950
Total assets	$	495,620		$	(887	)	$	494,733
Liabilities and shareholders’ equity
Total liabilities	$	167,989		$	—		$	167,989
Shareholders’ equity
Common shares	$	1,902		$	—		$	1,902
Additional paid-in capital		271,019			—			271,019
Retained earnings		57,749			(887	)		56,862
Accumulated other comprehensive loss		(3,039	)		—			(3,039	)
Total shareholders’ equity		327,631			(887	)		326,744
Total liabilities and shareholders’ equity	$	495,620		$	(887	)	$	494,733

Subsequent to the adoption of ASU 2016-13, the Company’s allowance for expected credit losses represents the portion of the receivable’s amortized cost basis that an entity does not expect to collect over the receivable’s contractual life, considering past events, current conditions, and reasonable and supportable forecasts of future economic conditions.

The process for estimating the ultimate collection of accounts receivable involves significant assumptions and judgments. The determination of the contractual life of accounts receivables, as well as the historical collections, write-offs, and payor reimbursement experience over the estimated contractual lives of such receivables, are integral parts of the estimation process related to reserves for expected credit losses and the establishment of contractual allowances. Accounts receivable are analyzed on a quarterly basis to assess the adequacy of both reserves for expected credit losses and contractual allowances. Revisions in allowances for expected credit loss estimates are recorded as an adjustment to bad debt expense within sales and marketing expenses. Revisions to contractual allowances are recorded as an adjustment to net sales. These estimates are periodically tested against actual collection experience. In addition, the Company analyzes its receivables by geography and by customer type, where appropriate, in developing estimates for expected credit losses.

The following table provides a detail of changes in the Company’s allowance for expected credit losses for the three months ended March 31, 2020:

The Company’s contract assets, excluding trade accounts receivable (“Other Contract Assets”), largely consist of payments made to certain distributors to obtain contracts, gain access to customers in certain territories, and to provide the benefit of the exclusive distribution of Orthofix products. Other Contract Assets are included in other long-term assets or other current assets, dependent upon the original term of the related agreement, and totaled $3.3 million and $3.7 million as of March 31, 2020, and December 31, 2019, respectively.