CASH AND CASH EQUIVALENTS

12 Months Ended

Dec. 31, 2017

Cash and Cash Equivalents [Abstract]

Cash and cash equivalents as of December 31, 2017 and 2016 consisted of the following (in thousands):



	December 31, 2017		December 31, 2016
Cash and cash equivalents:
Cash	$	283,085	$	119,778
Cash equivalents	264,765		152,423
Total cash and cash equivalents	$	547,850	$	272,201

As of December 31, 2017 and 2016, the Company had letters of credit collateralized fully by bank deposits which total $18.6 million and $17.3 million, respectively. These letters of credit primarily relate to lease agreements for certain of the Company’s offices, which are required to be maintained and issued to the landlords of each facility. Each letter of credit is subject to renewal annually until the applicable lease expires. As the bank deposits have restrictions on their use, they are classified as restricted cash on the Company's consolidated balance sheets.