Goodwill and Intangible Assets

The change in goodwill from December 31, 2017, to March 31, 2018, consisted of the following (in thousands):



	Carrying Value
Balance at December 31, 2017	$	458,737
Goodwill acquired	8,573
Purchase price allocation adjustments	39
Impact of foreign exchange rates	(735		)
Balance at March 31, 2018	$	466,614

As of March 31, 2018, goodwill allocated to the SBP and MI segments was $460.7 million and $5.9 million, respectively. As of December 31, 2017, goodwill allocated to the SBP and MI segments was $452.8 million and $5.9 million, respectively. Changes to initial purchase price allocations related to acquisitions may arise from changes in estimates from conditions that existed at the applicable acquisition date and as a result of net working capital adjustments.

Identifiable intangible assets that are separable and have determinable useful lives are valued separately and amortized over their benefit period. The following is the gross carrying value and accumulated amortization of the Company’s identifiable intangible assets as of March 31, 2018, and December 31, 2017 (in thousands):



	March 31, 2018							December 31, 2017
	Gross Carrying Amount		Accumulated Amortization			Net Carrying Amount		Gross Carrying Amount		Accumulated Amortization			Net Carrying Amount
Trade names	$	15,980	$	(8,068	)	$	7,912	$	15,980	$	(7,283	)	$	8,697
Customer relationships	260,564		(89,413		)	171,151		256,650		(78,406		)	178,244
Other intangible assets	3,649		(856		)	2,793		3,640		(811		)	2,829
	$	280,193	$	(98,337	)	$	181,856	$	276,270	$	(86,500	)	$	189,770

The weighted average amortization period of these intangible assets in the aggregate is 4.3 years.