Operating Leases

12 Months Ended

Dec. 31, 2015

We have a number of lease agreements covering office space and certain equipment that we account for as operating leases. A majority of the lease agreements for office space have rent escalations that increase monthly rent payments over the lease terms and provide for a renewal option under negotiated terms and conditions upon expiration. We record rental expense on a straight-line basis over the base, non-cancelable lease terms. We recognize any difference between the calculated expense and amount actually paid as accrued rent. We reflect accrued rent as a current or non-current liability, depending on its expected date of reversal.

Rent expense incurred under operating leases for the years ended December 31, 2015, 2014, and 2013 was $5.8 million, $5.1 million, and $3.5 million, respectively.

Associated with operating leases, we have received tenant improvement allowances from lessors. We record the value of these improvements as fixed assets when acquired and amortize the assets over the term of the lease. We record an offsetting obligation as deferred rent and amortize it as a reduction to lease expense on a straight-line basis over the lease term.

The following summarizes the future minimum lease payments for outstanding operating lease agreements as of December 31, 2015:



	(in thousands)
2016	$	7,620
2017	7,462
2018	6,786
2019	6,390
2020	4,809
Thereafter	14,310
	$	47,377