Stock-Based Compensation Plans and Arrangements - Stock Option Activity (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Number of Options
Outstanding at December 31, 2014	16,155,119
Granted	0
Exercised	(2,709,554)
Canceled	(1,534,589)
Outstanding at December 31, 2015	11,910,976	16,155,119
Exercisable at December 31, 2015	10,599,378
Weighted Average Exercise Price per Share
Outstanding at December 31, 2014 (in dollars per share)	$ 9.91
Granted (in dollars per share)	0.00
Exercised (in dollars per share)	4.76
Canceled (in dollars per share)	17.69
Outstanding at December 31, 2015 (in dollars per share)	10.08	$ 9.91
Exercisable at December 31, 2015 (in dollars per share)	$ 7.49
Weighted Average Remaining Contractual Term, Outstanding, ending balance	2 years 4 months 24 days
Weighted Average Remaining Contractual Term, Exercisable, ending balance	2 years 4 months 24 days
Aggregate Intrinsic Value, Outstanding, ending balance	$ 10,214,000
Aggregate Intrinsic Value, Exercisable, ending balance	10,137,000
Total intrinsic value of options exercised	13,700,000	$ 11,400,000	$ 8,500,000
Cash received from option exercises	0
Tax benefit realized from exercise of stock options	$ 3,700,000