Employee Benefits and Incentive Plans - Summary of Stock Option Activity under 2006 EIP and 2013 LTIP (Detail) - $ / shares	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted stock granted	(26,483)
Number of Shares, Options Exercised	(69,336)	(413,008)	(112,216)
2006 EIP and 2013 LTIP [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options Available for Grant, Beginning Balance	5,868,283
Options Available for Grant, Options granted	0
Options Available for Grant, Options exercised	0
Restricted stock granted	(666,733)
Restricted stock canceled	119,480
Options Available for Grant, Ending Balance	5,333,520	5,868,283
Number of Shares, Beginning Balance	2,280,030
Number of Options, Options Granted	0
Number of Shares, Options Exercised	(69,336)
Number of Shares, Ending Balance	2,169,305	2,280,030
Weighted Average Exercise Price, Beginning Balance	$ 27.08
Weighted Average Exercise Price, Granted	0
Weighted Average Exercise Price, Exercised	13.15
Weighted Average Exercise Price, Ending Balance	$ 27.45	$ 27.08
2013 LTIP [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options Available for Grant, Options Canceled or forfeited	12,490
Number of Shares, Options Canceled or forfeited	(12,490)
Weighted Average Exercise Price, Options Canceled or forfeited	$ 23.52
2006 EIP [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options Available for Grant, Options Canceled or forfeited	0
Number of Shares, Options Canceled or forfeited	(28,899)
Weighted Average Exercise Price, Options Canceled or forfeited	$ 33.70