Goodwill and Other Intangible Assets (Tables)

12 Months Ended

Dec. 31, 2016

Goodwill And Intangible Assets Disclosure [Abstract]

Changes in Goodwill

The following table shows the changes in goodwill by reportable segment and in total:

December 31	Mid- America Group			Southeast Group		West Group			Cement			Total
(add 000)	2016
Balance at beginning of period	$	281,403		$	50,346	$	871,220		$	865,266		$	2,068,235
Acquisitions		—			—		91,174			—			91,174
Divestitures		—			—		(72	)		—			(72	)
Balance at end of period	$	281,403		$	50,346	$	962,322		$	865,266		$	2,159,337
	2015
Balance at beginning of period	$	282,117		$	50,346	$	852,436		$	883,900		$	2,068,799
Acquisitions		—			—		8,464			—			8,464
Adjustments to purchase price allocations		—			—		15,538			(18,634	)		(3,096	)
Divestitures		(714	)		—		(5,218	)		—			(5,932	)
Balance at end of period	$	281,403		$	50,346	$	871,220		$	865,266		$	2,068,235

Intangible Assets Subject to Amortization

Intangible assets subject to amortization consist of the following:

December 31	Gross Amount		Accumulated Amortization			Net Balance
(add 000)	2016
Noncompetition agreements	$	6,274	$	(6,106	)	$	168
Customer relationships		45,755		(13,636	)		32,119
Operating permits		455,095		(19,493	)		435,602
Use rights and other		16,946		(9,239	)		7,707
Trade names		12,800		(5,681	)		7,119
Total	$	536,870	$	(54,155	)	$	482,715
	2015
Noncompetition agreements	$	6,274	$	(6,069	)	$	205
Customer relationships		35,805		(10,448	)		25,357
Operating permits		450,419		(12,294	)		438,125
Use rights and other		16,746		(8,030	)		8,716
Trade names		12,800		(3,408	)		9,392
Total	$	522,044	$	(40,249	)	$	481,795

Intangible Assets Deemed to Indefinite Life and Not Being Amortized

Intangible assets deemed to have an indefinite life and not being amortized consist of the following:

December 31	Aggregates Business		Cement		Magnesia Specialties		Total
(add 000)	2016
Operating permits	$	6,600	$	—	$	—	$	6,600
Use rights		10,015		9,137		—		19,152
Trade names		280		—		2,565		2,845
Total	$	16,895	$	9,137	$	2,565	$	28,597
	2015
Operating permits	$	6,600	$	—	$	—	$	6,600
Use rights		10,175		9,137		—		19,312
Trade names		280		—		2,565		2,845
Total	$	17,055	$	9,137	$	2,565	$	28,757

Schedule of Acquired Intangibles

During 2016, the Corporation acquired $15,134,000 of intangibles, consisting of the following:

(add 000, except year data)	Amount		Weighted-average amortization period
Subject to amortization:
Customer relationships	$	9,950	10.3 years
Operating permits		4,984	40.6 years
Other		200	1.5 years
Total	$	15,134	20.2 years

Estimated Amortization Expense of Intangible Assets

The estimated amortization expense for intangible assets for each of the next five years and thereafter is as follows:

(add 000)
2017	$	14,375
2018		13,417
2019		12,107
2020		11,727
2021		11,021
Thereafter		420,068
Total	$	482,715