Goodwill and Other Intangible Assets

Goodwill and other intangible assets, net of accumulated amortization, at September 30, 2018 and December 31, 2017 are as follows (in thousands):



	September 30, 2018		December 31, 2017
Goodwill	$	637,486	$	433,374
Other intangible assets, net	877,945		347,212
Total goodwill and other intangible assets, net	$	1,515,431	$	780,586

Additions to goodwill and other intangible assets in 2018 relate to the acquisition of Boat Holdings in July 2018. The aggregate purchase price was allocated on a preliminary basis to the assets acquired and liabilities assumed based on their estimated fair values at the date of acquisition. Boat Holding’s financial results are included in the Company’s consolidated results from the date of acquisition. As of September 30, 2018, the purchase price allocation remains preliminary. The pro forma financial results and the preliminary purchase price allocation are included in Note 3. There were no material additions to goodwill and other intangible assets for the three and nine months ended September 30, 2017.

The changes in the carrying amount of goodwill for the nine months ended September 30, 2018 were as follows (in thousands):



	Nine months ended September 30, 2018
Goodwill, beginning of period	$	433,374
Goodwill from businesses acquired	207,126
Currency translation effect on foreign goodwill balances	(3,014		)
Goodwill, end of period	$	637,486

The components of other intangible assets were as follows (in thousands):



	Total estimated life (years)	September 30, 2018			December 31, 2017
Non-amortizable—indefinite lived:
Brand names		$	440,976		$	230,709
Amortizable:
Non-compete agreements	4	2,370			540
Dealer/customer related	5-20	505,543			169,694
Developed technology	5-7	13,368			22,903
Total amortizable		521,281			193,137
Less: Accumulated amortization		(84,312		)	(76,634		)
Net amortized other intangible assets		436,969			116,503
Total other intangible assets, net		$	877,945		$	347,212

Amortization expense for intangible assets for the three and nine months ended September 30, 2018 was $10,403,000 and $22,586,000, respectively, compared to $6,344,000 and $18,792,000 for the comparable prior year periods. Estimated amortization expense for the remainder of 2018 through 2023 is as follows: 2018 (remainder), $10,500,000; 2019, $40,500,000; 2020, $35,500,000; 2021, $32,700,000; 2022, $27,700,000; 2023, $25,300,000; and after 2023, $264,800,000. The preceding expected amortization expense is an estimate and actual amounts could differ due to additional intangible asset acquisitions, changes in foreign currency rates or impairment of intangible assets.