Stockholders' Equity - Schedule of Dividends Paid (Detail) - $ / shares	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Dividends Payable [Line Items]
Dividend Per Share	$ 1.21	$ 1.09	$ 0.95
Installment One
Dividends Payable [Line Items]
Declaration Date	Feb. 18, 2016	Feb. 19, 2015
Record Date	Mar. 03, 2016	Mar. 05, 2015
Payment Date	Mar. 17, 2016	Mar. 19, 2015
Dividend Per Share	$ 0.28	$ 0.25
Installment Two
Dividends Payable [Line Items]
Declaration Date	Apr. 19, 2016	Apr. 20, 2015
Record Date	Jun. 02, 2016	Jun. 04, 2015
Payment Date	Jun. 16, 2016	Jun. 18, 2015
Dividend Per Share	$ 0.31	$ 0.28
Installment Three
Dividends Payable [Line Items]
Declaration Date	Jul. 21, 2016	Jul. 23, 2015
Record Date	Aug. 25, 2016	Aug. 27, 2015
Payment Date	Sep. 08, 2016	Sep. 10, 2015
Dividend Per Share	$ 0.31	$ 0.28
Installment Four
Dividends Payable [Line Items]
Declaration Date	Oct. 20, 2016	Oct. 29, 2015
Record Date	Nov. 22, 2016	Nov. 24, 2015
Payment Date	Dec. 06, 2016	Dec. 08, 2015
Dividend Per Share	$ 0.31	$ 0.28