CASH, CASH EQUIVALENTS, RESTRICTED CASH AND MARKETABLE SECURITIES

The Company considers all highly liquid investments purchased with an original maturity of three months or less to be cash equivalents and those investments with original maturities greater than three months to be marketable securities. Cash and cash equivalents consisted of money market instruments and cash maintained with various financial institutions at December 31, 2017 and March 31, 2017.

Cash, Cash Equivalents and Restricted Cash

The following table provides a reconciliation of cash, cash equivalents and restricted cash reported within the consolidated balance sheets that sum to the total of the same such amounts shown in the consolidated statements of cash flows (in thousands):



	December 31, 2017		March 31, 2017		December 31, 2016		March 31, 2016
Cash and cash equivalents	$	331,912	$	304,880	$	244,833	$	210,711
Restricted cash	910		846		846		186
Total cash, cash equivalents and restricted cash	$	332,822	$	305,726	$	245,679	$	210,897

The Company's restricted cash includes cash balances which are legally or contractually restricted. The Company's restricted cash is included within prepaid and other current assets and consists of amounts related to holdbacks associated with prior acquisitions.

Marketable Securities

The following is a summary of marketable securities held by NetScout at December 31, 2017, classified as short-term and long-term (in thousands):



	Amortized Cost		Unrealized Losses			Fair Value
Type of security:
U.S. government and municipal obligations	$	41,957	$	(74	)	$	41,883
Commercial paper	5,007		—			5,007
Corporate bonds	1,006		(1		)	1,005
Total short-term marketable securities	47,970		(75		)	47,895
U.S. government and municipal obligations	3,203		(16		)	3,187
Total long-term marketable securities	3,203		(16		)	3,187
Total marketable securities	$	51,173	$	(91	)	$	51,082

The following is a summary of marketable securities held by NetScout at March 31, 2017, classified as short-term and long-term (in thousands):



	Amortized Cost		Unrealized Losses			Fair Value
Type of security:
U.S. government and municipal obligations	$	98,989	$	(21	)	$	98,968
Commercial paper	29,469		—			29,469
Corporate bonds	7,959		(3		)	7,956
Certificates of deposit	1,499		—			1,499
Total short-term marketable securities	137,916		(24		)	137,892
U.S. government and municipal obligations	21,952		(19		)	21,933
Total long-term marketable securities	21,952		(19		)	21,933
Total marketable securities	$	159,868	$	(43	)	$	159,825

Contractual maturities of the Company's marketable securities held at December 31, 2017 and March 31, 2017 were as follows (in thousands):



	December 31, 2017		March 31, 2017
Available-for-sale securities:
Due in 1 year or less	$	47,895	$	137,892
Due after 1 year through 5 years	3,187		21,933
	$	51,082	$	159,825