Compensation Plans - Summary of Nonvested Options (Detail) - $ / shares	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Number of Options
Number of options outstanding, beginning balance (in shares)	9,117,733	9,205,690	9,235,320
Number of options granted (in shares)	1,364,916	1,884,262	1,242,428
Number of options, canceled or expired (in shares)	(301,929)	(232,372)	(180,312)
Number of options outstanding, ending balance (in shares)	8,770,917	9,117,733	9,205,690
Non Vested Options [Member]
Number of Options
Number of options outstanding, beginning balance (in shares)	2,576,504	2,045,795	2,066,231
Number of options granted (in shares)	1,364,916	1,884,262	1,242,428
Number of options, vested (in shares)	(1,016,923)	(1,121,181)	(1,082,552)
Number of options, canceled or expired (in shares)	(301,929)	(232,372)	(180,312)
Number of options outstanding, ending balance (in shares)	2,622,568	2,576,504	2,045,795
Weighted Average Grant-Date Fair Value Per Share
Weighted average grant-date fair value per share, nonvested beginning balance (in dollars per share)	$ 12.95	$ 12.55	$ 12.61
Weighted average grant-date fair value per share, granted (in dollars per share)	15.33	13.58	11.86
Weighted average grant-date fair value per share, vested (in dollars per share)	12.78	13.24	11.71
Weighted average grant-date fair value per share, cancelled or expired (in dollars per share)	14.18	13.05	13.56
Weighted average grant-date fair value per share, nonvested ending balance (in dollars per share)	$ 14.12	$ 12.95	$ 12.55