Income Taxes - Income Taxes Expense from Continuing Operations (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014		Dec. 31, 2013
Income Tax Disclosure [Abstract]
Current income tax expense	$ 174,284	$ 169,319		$ 190,406
Deferred income tax expense	75,610	87,284		57,704
Income tax expense from continuing operations	$ 249,894	$ 256,603	[1]	$ 248,110	[1]

[1] Certain balances were adjusted to give effect to discontinued operations and the adoption of new accounting guidance as described in Note 1- Significant Accounting Policies under the caption "Low-Income Housing Tax Credit Interests."