
	For the three months ended June 30,						For the six months ended June 30,
	2020		2019		2020		2019
Cost of sales - equipment (exclusive of depreciation and amortization)	$	3,913	$	6,316	$	10,605	$	11,711
Research and development expenses	$	7,448	$	6,388	$	13,702	$	13,276

The following table reconciles Cash and cash equivalents and restricted cash, as presented in the Condensed Consolidated Balance Sheets, to the total of the same as presented in the Condensed Consolidated Statements of Cash Flows:


	For the six months ended June 30,
	2020		2019
Cash and cash equivalents, including restricted amounts, beginning of period:
Cash and cash equivalents	$	1,519,431	$	928,306
Restricted cash	2,458		1,189
Total cash and cash equivalents, included restricted amounts, beginning of period	$	1,521,889	$	929,495

Cash and cash equivalents, including restricted amounts, end of period:
Cash and cash equivalents	$	1,948,464	$	1,298,005
Restricted cash	9,072		9,121
Total cash and cash equivalents, included restricted amounts, end of period	$	1,957,536	$	1,307,126


	As of
	June 30, 2020		December 31, 2019
Other current assets, net:
Trade accounts receivable - DISH Network	$	13,465	$	10,683
Inventory	83,559		79,621
Prepaids and deposits	47,614		50,145
Contract acquisition costs, net	16,380		16,869
Other, net	24,681		22,213
Total other current assets, net	$	185,699	$	179,531

Other non-current assets, net:
Other receivables - DISH Network	$	93,705	$	92,892
Restricted marketable investment securities	731		8,093
Restricted cash	9,072		2,458
Deferred tax assets, net	9,311		7,251
Capitalized software, net	109,091		101,786
Contract acquisition costs, net	90,706		96,723
Contract fulfillment costs, net	2,677		3,010
Other, net	25,611		22,628
Total other non-current assets, net	$	340,904	$	334,841

The following table presents the activity in our allowance for doubtful accounts, which is included within Other, net in each of Other current assets, net and Other non-current assets, net in the table above:


	For the six months ended June 30, 2020
	Other current assets, net		Other non-current assets, net
Balance at beginning of period	$	—	$	—
Credit losses ⁽¹⁾	1,595		13,378

Foreign currency translation	152		(572)
Balance at end of period	$	1,747	$	12,806

⁽¹⁾The impact of adopting ASC 326 on January 1, 2020 was a net increase to our allowance for doubtful accounts largely driven by a $13.4 million reclassification from Trade accounts receivables and contracts assets, net.


	As of
	June 30, 2020		December 31, 2019
Accrued expenses and other current liabilities:
Trade accounts payable - DISH Network	$	2,317	$	1,923
Accrued interest	41,633		42,622
Accrued compensation	49,042		50,787
Accrued taxes	19,175		18,525
Operating lease obligation	14,305		14,651
Other	136,472		142,371
Total accrued expenses and other current liabilities	$	262,944	$	270,879


	As of
	June 30, 2020		December 31, 2019
Raw materials	$	6,508	$	4,240
Work-in-process	7,553		6,979
Finished goods	69,498		68,402
Total inventory	$	83,559	$	79,621


	For the six months ended June 30,
	2020		2019
Supplemental disclosure of cash flow information:
Cash paid for interest, net of amounts capitalized	$	72,450	$	120,625
Cash paid for income taxes	$	2,422	$	1,217

Non-cash investing and financing activities:
Employee benefits paid in Class A common stock	$	6,920	$	6,654

Increase (decrease) in capital expenditures included in accounts payable, net	$	2,055	$	(15,839)


Non-cash net assets received in exchange for a 20% ownership interest in our existing Brazilian subsidiary	$	2,824	$	—