Goodwill and Intangible Assets, Net

Goodwill

The following table presents the changes in the carrying amount of our goodwill (in thousands):



	Total
Balance as of January 1, 2019	$	11,195
Currency translation	46
Balance as of March 31, 2019	$	11,241

Intangible Assets, Net

Intangible assets, carried at cost less accumulated amortization and amortized on a straight-lined basis, were as follows (in thousands):



	Weighted Average	March 31, 2019
	Amortization Life in Years	Cost		Accumulated Amortization		Net
Patents	10	$	20,314	$	12,475	$	7,839
Customer contracts	9	5,319		5,319		—
Non-contractual customer relationships	9	57,949		15,080		42,869
Trademarks	4	425		425		—
Trade name	15	7,456		1,747		5,709
Developed technology	11	82,507		17,140		65,367
Total amortized intangible assets		$	173,970	$	52,186	$	121,784

IPR&D		$	9,269	—		$	9,269

Total intangible assets		$	183,239	$	52,186	$	131,053



	Weighted Average	December 31, 2018
	Amortization Life in Years	Cost		Accumulated Amortization		Net
Patents	10	$	19,399	$	12,147	$	7,252
Customer contracts	9	5,319		5,272		47
Non-contractual customer relationships	9	57,916		13,363		44,553
Trademarks	4	425		425		—
Trade name	15	7,456		1,618		5,838
Developed technology	11	82,857		15,361		67,496
Total amortized intangible assets		$	173,372	$	48,186	$	125,186

IPR&D		$	8,235			$	8,235

Total intangible assets		$	181,607	$	48,186	$	133,421

Intangible assets with definite lives are amortized on a straight-line basis over their estimated useful lives. Intangible asset amortization expense was $4.0 million and $4.1 million for the three months ended March 31, 2019, and 2018, respectively.

As of March 31, 2019 estimated annual amortization for our intangible assets for each of the next five years is approximately (in thousands):



Remainder of 2019	$	17,048
2020	16,099
2021	15,897
2022	15,773
2023	15,624
Thereafter	41,343
Total	$	121,784