Unaudited Selected Quarterly Data (Tables)

12 Months Ended

Dec. 31, 2018

Dec. 31, 2017

New Accounting Pronouncements or Change in Accounting Principle [Line Items]

Quarterly Financial Information [Text Block]

Unaudited quarterly financial results are set forth in the following tables. It is legacy Northrop Grumman’s long-standing practice to establish actual interim closing dates using a “fiscal” calendar in which we close our books on a Friday near each quarter-end date, in order to normalize the potentially disruptive effects of quarterly closings on business processes. Similarly, Innovation Systems uses a “fiscal” calendar by closing its books on a Sunday near these quarter-end dates and will continue this practice until its business processes are aligned with legacy Northrop Grumman’s. This practice is only used at interim periods within a reporting year.



2018
In millions, except per share amounts	1st Qtr		2nd Qtr⁽¹⁾		3rd Qtr⁽¹⁾		4th Qtr⁽¹⁾
Sales	$	6,735	$	7,119	$	8,085	$	8,156
Operating income	848		817		1,172		943
Net earnings	840		789		1,244		356

Basic earnings per share	4.82		4.52		7.15		2.07
Diluted earnings per share	4.79		4.50		7.11		2.06

Weighted-average common shares outstanding	174.3		174.5		174.1		171.8
Weighted-average diluted shares outstanding	175.4		175.4		174.9		172.6



2018 - Impact of Accounting Change⁽²⁾
In millions, except per share amounts	1st Qtr			2nd Qtr			3rd Qtr			4th Qtr
Sales	$	—		$	—		$	—		$	—
Operating income	(6		)	(6		)	(6		)	23
Net earnings	101			100			100			(394		)

Basic earnings per share	0.58			0.57			0.58			(2.29		)
Diluted earnings per share	0.58			0.57			0.57			(2.28		)



2017
In millions, except per share amounts	1st Qtr		2nd Qtr		3rd Qtr		4th Qtr
Sales	$	6,410	$	6,473	$	6,569	$	6,552
Operating income	853		864		829		672
Net earnings	770		677		750		672

Basic earnings per share	4.41		3.88		4.31		3.86
Diluted earnings per share	4.37		3.86		4.28		3.83

Weighted-average common shares outstanding	174.8		174.5		174.2		174.2
Weighted-average diluted shares outstanding	176.1		175.5		175.3		175.5



2017 - Impact of Accounting Change⁽²⁾
In millions, except per share amounts	1st Qtr			2nd Qtr			3rd Qtr			4th Qtr
Sales	$	—		$	—		$	—		$	—
Operating income	(9		)	(9		)	(8		)	(32		)
Net earnings	120			122			107			525

Basic earnings per share	0.69			0.70			0.62			3.01
Diluted earnings per share	0.68			0.70			0.61			2.99

⁽¹⁾ Selected financial data includes the operating results of Innovation Systems subsequent to the Merger date.

⁽²⁾ Table reflects the effects of the Accounting change described in Note 1 on our unaudited selected quarterly financial data.

Quarterly Financial Information [Table Text Block]



2018
In millions, except per share amounts	1st Qtr		2nd Qtr⁽¹⁾		3rd Qtr⁽¹⁾		4th Qtr⁽¹⁾
Sales	$	6,735	$	7,119	$	8,085	$	8,156
Operating income	848		817		1,172		943
Net earnings	840		789		1,244		356

Basic earnings per share	4.82		4.52		7.15		2.07
Diluted earnings per share	4.79		4.50		7.11		2.06

Weighted-average common shares outstanding	174.3		174.5		174.1		171.8
Weighted-average diluted shares outstanding	175.4		175.4		174.9		172.6



2017
In millions, except per share amounts	1st Qtr		2nd Qtr		3rd Qtr		4th Qtr
Sales	$	6,410	$	6,473	$	6,569	$	6,552
Operating income	853		864		829		672
Net earnings	770		677		750		672

Basic earnings per share	4.41		3.88		4.31		3.86
Diluted earnings per share	4.37		3.86		4.28		3.83

Weighted-average common shares outstanding	174.8		174.5		174.2		174.2
Weighted-average diluted shares outstanding	176.1		175.5		175.3		175.5

Adjustments for change to Defined Benefit Plan, Actuarial Gain (Loss), Immediate Recognition as Component in Net Period Benefit (Cost) [Member] | Adjustments for Change in Accounting Principle [Domain]

New Accounting Pronouncements or Change in Accounting Principle [Line Items]

Quarterly Financial Information [Text Block]



2017 - Impact of Accounting Change⁽²⁾
In millions, except per share amounts	1st Qtr			2nd Qtr			3rd Qtr			4th Qtr
Sales	$	—		$	—		$	—		$	—
Operating income	(9		)	(9		)	(8		)	(32		)
Net earnings	120			122			107			525

Basic earnings per share	0.69			0.70			0.62			3.01
Diluted earnings per share	0.68			0.70			0.61			2.99

Quarterly Financial Information [Table Text Block]



2018 - Impact of Accounting Change⁽²⁾
In millions, except per share amounts	1st Qtr			2nd Qtr			3rd Qtr			4th Qtr
Sales	$	—		$	—		$	—		$	—
Operating income	(6		)	(6		)	(6		)	23
Net earnings	101			100			100			(394		)

Basic earnings per share	0.58			0.57			0.58			(2.29		)
Diluted earnings per share	0.58			0.57			0.57			(2.28		)