Stockholders' Equity - Additional Information (Detail) - USD ($)				1 Months Ended	6 Months Ended	44 Months Ended
	May 24, 2017	Feb. 28, 2017	Feb. 14, 2017	May 31, 2017	Jun. 30, 2017	Jun. 30, 2017	Dec. 31, 2016	Jul. 31, 2015
Class Of Stock [Line Items]
Preferred stock, authorized					1,000,000	1,000,000
Preferred stock, par value					$ 0.01	$ 0.01
Preferred stock, shares issued					0	0	0
Preferred stock, shares outstanding					0	0	0
Q2 Solutions [Member]
Class Of Stock [Line Items]
Percentage of Quest's non-controlling interest in Q2 Solutions								40.00%
Quest's non-controlling interest in Q2 Solutions					$ 235,000,000
Quest [Member]
Class Of Stock [Line Items]
Ownership percentage								60.00%
Secondary Public Offering [Member]
Class Of Stock [Line Items]
Repurchase of stock, shares				3,571,003
Repurchase of stock, value				$ 300,000,000
Common stock held by Selling Stockholders underwritten				10,571,003
Registration statement expiration period after filing date					3 years
Equity Repurchase Program [Member]
Class Of Stock [Line Items]
Equity repurchase program increase in authorized amount	$ 1,000,000,000		$ 1,000,000,000
Equity repurchase program authorized amount	$ 4,225,000,000
Repurchase of stock, shares		9,677,420			21,337,443
Repurchase of common stock, share price					$ 79.40
Repurchase of stock, value		$ 750,000,000			$ 1,700,000,000	$ 3,372,000,000
Equity available for repurchase under the repurchase program					$ 853,000,000	853,000,000
Equity Repurchase Program [Member] | Stock Options [Member]
Class Of Stock [Line Items]
Repurchase of stock, value						59,000,000
Equity Repurchase Program [Member] | Common Stock [Member]
Class Of Stock [Line Items]
Repurchase of stock, value						$ 3,313,000,000