OTHER ASSETS

Other assets at September 30, 2014 and December 31, 2013 consisted of the following (in thousands):



	September 30, 2014		December 31, 2013
Deferred debt issuance costs	$	28,012	$	16,465
Security deposits	12,697		10,617
Other	7,762		6,432
Total	$	48,471	$	33,514

Deferred debt issuance costs arose from (i) the $1.0 billion aggregate principal amount of 1.0% Convertible Senior Notes, due March 15, 2018, issued in March 2012; (ii) a $1.0 billion revolving credit facility entered into in October 2011; (iii) the $575.0 million aggregate principal amount of 1.25% Convertible Senior Notes, due March 15, 2015, issued in March 2010; (iv) the $1.0 billion aggregate principal amount of 0.35% Convertible Senior Notes, due June 15, 2020, issued in May 2013; (v) the $1.0 billion aggregate principal amount of 0.9% Convertible Senior Notes, due September 15, 2021, issued in August 2014; and (vi) the 1.0 billion Euro aggregate principal amount of 2.375% Senior Notes, due September 23, 2024, issued in September 2014. Deferred debt issuance costs are being amortized using the effective interest rate method and the period of amortization was determined at inception of the related debt agreements based upon the stated maturity dates. Unamortized debt issuance costs written off to interest expense in the nine months ended September 30, 2014 related to early conversion of convertible debt amounted to $0.5 million. Security deposits principally relate to the Company's leased office spaces.