Operating Segments Operating Segments (Tables)

3 Months Ended

6 Months Ended

Jun. 30, 2018

Jun. 30, 2018

Schedule of Segment Reporting Information, by Segment [Table Text Block]

	Three Months Ended June 30, 2018								Three Months Ended June 30, 2017
	Towers		Fiber		Other		Consolidated Total		Towers		Fiber		Other		Consolidated Total
Segment site rental revenues	$	771	$	398			$	1,169	$	718	$	151			$	869
Segment network services and other revenues	158		3				161		158		11				169
Segment revenues	929		401				1,330		876		162				1,038
Segment site rental cost of operations	216		130				346		211		52				263
Segment network services and other cost of operations	94		3				97		96		8				104
Segment cost of operations(a)(b)	310		133				443		307		60				367
Segment site rental gross margin	555		268				823		507		99				606
Segment network services and other gross margin	64		—				64		62		3				65
Segment general and administrative expenses(b)	27		44				71		23		19				42
Segment operating profit (loss)	592		224				816		546		83				629
Other general and administrative expenses(b)					$	47	47						$	41	41
Stock-based compensation expense					26		26						17		17
Depreciation, amortization and accretion					379		379						296		296
Interest expense and amortization of deferred financing costs					158		158						142		142
Other income (expenses) to reconcile to income (loss) before income taxes(c)					21		21						16		16
Income (loss) before income taxes							$	185							$	117
Capital expenditures	$	98	$	289	$	6	$	393	$	107	$	188	$	6	$	301
Total assets (at period end)	$	17,780	$	14,100	$	494	$	32,374	$	18,208	$	5,811	$	465	$	24,484

(a) Exclusive of depreciation, amortization and accretion shown separately.

(b) Segment cost of operations excludes (1) stock-based compensation expense of $6 million and $2 million for the three months ended June 30, 2018 and 2017, respectively, and (2) prepaid lease purchase price adjustments of $5 million for both of the three months ended June 30, 2018 and 2017. General and administrative expenses exclude stock-based compensation expense of $20 million and $15 million for the three months ended June 30, 2018 and 2017, respectively.

(c) See condensed consolidated statement of operations for further information.

	Six Months Ended June 30, 2018								Six Months Ended June 30, 2017
	Towers		Fiber		Other		Consolidated Total		Towers		Fiber		Other		Consolidated Total
Segment site rental revenues	$	1,536	$	787			$	2,323	$	1,434	$	292			$	1,726
Segment network services and other revenues	300		7				307		308		20				328
Segment revenues	1,836		794				2,630		1,742		312				2,054
Segment site rental cost of operations	427		256				683		420		99				519
Segment network services and other cost of operations	176		5				181		185		17				202
Segment cost of operations(a)(b)	603		261				864		605		116				721
Segment site rental gross margin	1,109		531				1,640		1,014		193				1,207
Segment network services and other gross margin	124		2				126		123		3				126
Segment general and administrative expenses(b)	53		87				140		47		36				83
Segment operating profit (loss)	1,180		446				1,626		1,090		160				1,250
Other general and administrative expenses(b)					$	94	94						$	80	80
Stock-based compensation expense					52		52						42		42
Depreciation, amortization and accretion					753		753						584		584
Interest expense and amortization of deferred financing costs					318		318						276		276
Other income (expenses) to reconcile to income (loss) before income taxes(c)					106		106						28		28
Income (loss) before income taxes							$	303							$	240
Capital expenditures	$	195	$	552	$	16	$	763	$	208	$	342	$	13	$	563

(a) Exclusive of depreciation, amortization and accretion shown separately.

(b) Segment cost of operations excludes (1) stock-based compensation expense of $13 million and $6 million for the six months ended June 30, 2018 and 2017, respectively, and (2) prepaid lease purchase price adjustments of $10 million for both of the six months ended June 30, 2018 and 2017. General and administrative expenses exclude stock-based compensation expense of $39 million and $36 million for the six months ended June 30, 2018 and 2017, respectively.

(c) See condensed consolidated statement of operations for further information.