5. Patents and Licenses

3 Months Ended

Mar. 31, 2017

Patents And Licenses

Patents and Licenses

Purchased patents and licenses paid for the use of other entities’ patents are amortized over the useful life of the patent or license. The following tables provide information regarding patents and licenses (dollars in thousands):

March 31, 2017						December 31, 2016
Weighted Average Original Life (years)		Gross Carrying Amount		Accumulated Amortization		Weighted Average Original Life (years)		Gross Carrying Amount		Accumulated Amortization
	15.67	$	13,840	$	11,972		15.67	$	13,840	$	11,911

Aggregate amortization expense for patents and licenses was $62,000 and $63,000 for the three months ended both March 31, 2017 and 2016, respectively.

Estimated future amortization expense for each of the years set forth below ending December 31 is as follows (in thousands):

2018	$119
2019	$119

2020	$119
2021	$119

2022                                            $117