Intangible Assets (Tables)

9 Months Ended

Sep. 30, 2019

Goodwill and Intangible Assets Disclosure [Abstract]

Schedule of gross carrying amount and related accumulated amortization of the intangible assets

The following sets forth the gross carrying amount and related accumulated amortization of the intangible assets, in thousands of dollars:

	Weighted- Average Life	September 30, 2019			December 31, 2018
	(unaudited)
Capitalized patent defense costs	3.26 - 7.51 years	$	43,375		$	44,724
Less accumulated amortization		(17,274		)	(13,356		)
Total		$	26,101		$	31,368