Earnings Per Common Share (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Earnings Per Share Reconciliation
Net income available to common shareholders	$ 33,937	$ 27,682	$ 96,269	$ 91,037
Basic weighted average number of common shares outstanding (in shares)	232,737,953	200,614,091	232,548,840	200,406,801
Plus: Common stock equivalents (in shares)	42,266	0	16,855	0
Diluted weighted average number of common shares outstanding (in shares)	232,780,219	200,614,091	232,565,695	200,406,801
Earnings per common share:
Basic (in usd per share)	$ 0.15	$ 0.14	$ 0.41	$ 0.45
Diluted (in usd per share)	$ 0.15	$ 0.14	$ 0.41	$ 0.45
Anti-dilutive common stock options and warrants (in shares)	5,000,000	6,600,000	5,000,000	6,600,000