Goodwill and Other Long-Lived Assets (Tables)

9 Months Ended

Sep. 30, 2016

Goodwill and Intangible Assets Disclosure [Abstract]

The following table presents the changes in the carrying amount of our goodwill for the nine months ended September 30, 2016 (in thousands):



	Animal Hospital		Laboratory		All Other			Total
Balance as of December 31, 2015
Goodwill	$	1,402,106	$	101,269	$	144,332		$	1,647,707
Accumulated impairment losses	—		—		(130,057		)	(130,057		)
Subtotal	1,402,106		101,269		14,275			1,517,650
Goodwill acquired	536,060		—		941			537,001
Foreign translation adjustment	6,657		24		—			6,681
Other ⁽¹⁾	2,162		—		—			2,162
Balance as of September 30, 2016
Goodwill	1,946,985		101,293		145,273			2,193,551
Accumulated impairment losses	—		—		(130,057		)	(130,057		)
Subtotal	$	1,946,985	$	101,293	$	15,216		$	2,063,494

____________________________


⁽¹⁾	"Other" consists primarily of measurement period adjustments.

Summary of Other Intangible Assets

Our acquisition related amortizable intangible assets at September 30, 2016 and December 31, 2015 are as follows (in thousands):



	As of September 30, 2016							As of December 31, 2015
	Gross Carrying Amount		Accumulated Amortization			Net Carrying Amount		Gross Carrying Amount		Accumulated Amortization			Net Carrying Amount
Non-contractual customer relationships	$	214,050	$	(61,153	)	$	152,897	$	116,082	$	(48,821	)	$	67,261
Covenants not-to-compete	22,613		(6,997		)	15,616		12,435		(4,779		)	7,656
Favorable lease assets	9,457		(5,751		)	3,706		9,441		(5,440		)	4,001
Technology	1,377		(748		)	629		1,377		(589		)	788
Trademarks	29,525		(6,604		)	22,921		10,551		(4,086		)	6,465
Franchise rights	11,730		(2,444		)	9,286		11,730		(1,564		)	10,166
Total	$	288,752	$	(83,697	)	$	205,055	$	161,616	$	(65,279	)	$	96,337

Estimated Amortization Expense Related to Intangible Assets

The following table summarizes our aggregate amortization expense related to acquisition related intangible assets (in thousands):



	Three Months Ended September 30,				Nine Months Ended September 30,
	2016		2015		2016		2015
Aggregate amortization expense	$	10,682	$	5,811	$	26,709	$	17,195

Estimated Amortization Expense Related to Indefinite Intangible Assets

The estimated amortization expense related to acquisition related intangible assets for the remainder of 2016 and each of the succeeding years thereafter, as of September 30, 2016, is as follows (in thousands):



Finite-lived intangible assets:
Remainder of 2016	$	11,109
2017	40,011
2018	36,554
2019	33,544
2020	28,711
Thereafter	55,126
Total	$	205,055
Indefinite-lived intangible assets:
Trademarks	4,040
Total intangible assets	$	209,095