DEFERRED CHARGES AND OTHER NON-CURRENT ASSETS

Deferred charges and other non-current assets at December 31, 2013 and March 31, 2014 were as follows (in thousands):



	December 31, 2013		March 31, 2014
Prepaid agreements not to compete, net of accumulated amortization of $4,807 and $4,947, respectively	$	1,299	$	1,354
Deferred loan costs, net of accumulated amortization of $1,252 and $1,423, respectively	2,602		2,431
Convertible junior subordinated debenture origination costs, net of accumulated amortization of $1,095	2,949		—
Convertible subordinated notes issuance costs, net of accumulated amortization of $44	—		3,940
Tradenames	5,430		5,411
Other	—		280
Deferred charges and other non-current assets	$	12,280	$	13,416

Agreements not to compete are amortized over the term of the respective agreements, ranging generally from one to ten years. Amortization expense was $19,800 and $140,000 for the three months ended March 31, 2013 and 2014, respectively. Deferred loan costs are being amortized over the term of the related debt using the effective interest method. In connection with the redemption of our convertible junior subordinated debentures, we wrote-off the related unamortized origination costs of approximately $2.9 million in March 2014. The debt issuance costs related to our convertible subordinated notes issued in March 2014 are being amortized using the effective interest method over the seven year term of the notes. Our tradenames have indefinite lives and therefore are not amortized.