Goodwill and Intangible Assets (Tables)

6 Months Ended

Jul. 29, 2018

Goodwill and Intangible Assets Disclosure [Abstract]

Changes in Carrying Amounts of Goodwill

Changes in the carrying amount of goodwill by applicable reporting unit were as follows:

(in thousands)	Signal Integrity		Wireless and Sensing		Protection		Total
Balance at January 28, 2018	$	274,085	$	67,812	$	—	$	341,897
Additions	—		—		4,834		4,834
Balance at July 29, 2018	$	274,085	$	67,812	$	4,834	$	346,731

Schedule of Finite-lived Intangible Assets Acquired

The following table sets forth the Company’s finite-lived intangible assets resulting from business acquisitions, which continue to be amortized:

		July 29, 2018							January 28, 2018
(in thousands)	Estimated Useful Life	Gross Carrying Amount		Accumulated Amortization			Net Carrying Amount		Gross Carrying Amount		Accumulated Amortization			Net Carrying Amount
Core technologies	5-8 years	$	164,930	$	(126,203	)	$	38,727	$	164,930	$	(115,628	)	$	49,302
Customer relationships	3-10 years	34,031		(28,292		)	5,739		34,031		(25,426		)	8,605
Total finite-lived intangible assets		$	198,961	$	(154,495	)	$	44,466	$	198,961	$	(141,054	)	$	57,907

Amortization expenses recorded in the Statements of Income for each period were as follows:

	Three Months Ended				Six Months Ended
(in thousands)	July 29, 2018		July 30, 2017		July 29, 2018		July 30, 2017
Core technologies	$	5,047	$	5,464	$	10,575	$	10,650
Customer relationships	1,433		1,211		2,866		2,311
Total amortization expense	$	6,480	$	6,675	$	13,441	$	12,961

Schedule of Indefinite-Lived Intangible Assets

The following table sets forth the Company’s indefinite-lived intangible assets resulting from additions to IPR&D:

(in thousands)	Net Carrying Value
Value at January 28, 2018	$	2,300
In-process research and development through acquisitions	—
Value at July 29, 2018	$	2,300