Earnings Per Share - Summary of Earnings Per Share, Basic and Diluted (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2019		Mar. 31, 2018
Earnings Per Share [Abstract]
Net income	$ 172,107	[1]	$ 174,937
Denominator for basic earnings per share (in shares)	85,941		89,765
Dilutive securities (in shares)	3,303		3,485
Denominator for diluted earnings per share (in shares)	89,244		93,250
Basic earnings per share (in dollars per share)	$ 2.00		$ 1.95
Diluted earnings per share (in dollars per share)	$ 1.93		$ 1.88

[1] Reflects the impact of the Company's adoption of Accounting Standards Update 2016-18, "Statement of Cash Flows (Topic 230)", which was adopted by the Company on January 1, 2018 and applied retrospectively to results for 2017. The adoption of Topic 230 resulted in the statement of cash flows presenting the changes in the total of cash, cash equivalents and restricted cash. As a result, the Company will no longer present transfers between cash and cash equivalents and restricted cash in the statement of cash flows.