Goodwill and Intangible Assets (Tables)

12 Months Ended

Dec. 31, 2015

Goodwill and Finite-Lived Intangible Assets [Line Items]

Goodwill

The changes in the carrying value of goodwill for the years ended December 31, 2015 and December 31, 2014 were as follows:



Balance as of December 31, 2013	$	4,902,950
Adjustments to AT&T Acquisition purchase price allocation	134,242
Additions due to other acquisitions	159,362
Other adjustments, net	(69		)
Balance as of December 31, 2014	$	5,196,485
Additions due to Sunesys Acquisition^(a)	325,696
Additions due to other acquisitions	41,542
Adjustments to purchase price allocations, net	(50,172		)
Balance as of December 31, 2015	$	5,513,551


(a)	The purchase price allocation for the Sunesys Acquisition resulted in the recognition of goodwill based on the Company's expectation to leverage the Sunesys fiber footprint to support new small cell networks. The Sunesys fiber is complementary to the Company's existing fiber assets and is located where the Company expects to see wireless carrier network investments. See note 4.

Intangible Assets

The following is a summary of the Company's intangible assets. See note 4 for further discussion of the Company's acquisitions.



	As of December 31, 2015							As of December 31, 2014
	Gross Carrying Value		Accumulated Amortization			Net Book Value		Gross Carrying Value		Accumulated Amortization			Net Book Value
Site rental contracts and customer relationships	$	5,009,241	$	(1,588,061	)	$	3,421,180	$	4,627,429	$	(1,340,285	)	$	3,287,144
Other intangible assets	482,142		(123,407		)	358,735		496,284		(101,877		)	394,407
Total	$	5,491,383	$	(1,711,468	)	$	3,779,915	$	5,123,713	$	(1,442,162	)	$	3,681,551

Schedule of Amortization Expense

Amortization expense related to intangible assets is classified as follows on the Company's consolidated statement of operations and comprehensive income (loss):



	For Years Ended December 31,
Classification	2015		2014		2013
Depreciation, amortization and accretion	$	251,443	$	242,967	$	197,906
Site rental costs of operations	20,420		22,105		10,197
Total amortization expense	$	271,863	$	265,072	$	208,103

Site Rental Contracts and Customer Relationships [Member]

Goodwill and Finite-Lived Intangible Assets [Line Items]

Schedule of Estimated Annual Amortization Expense

The estimated annual amortization expense related to intangible assets (inclusive of those recorded as an increase to "site rental costs of operations") for the years ended December 31, 2016 to 2020 is as follows:



	Years Ending December 31,
	2016		2017		2018		2019		2020
Estimated annual amortization	$	272,067	$	271,503	$	271,054	$	270,618	$	270,188