Income Taxes (Tables)

6 Months Ended

Jun. 30, 2018

Income Tax Disclosure [Abstract]

Summary of Effective Income Tax Rate

The effective income tax rate differed from the expected rate for the three and six month periods ended June 30, 2018 and 2017 as shown below:

	Three Months Ended June 30,
	2018			%		2017			%
Expected income taxes	$	47,641		21.0		$	70,674		35.0
Increase (reduction) in income taxes resulting from:
Low income housing investments	(3,324		)	(1.5	)	(4,649		)	(2.3	)
Share-based awards	(2,055		)	(0.9	)	(4,018		)	(2.0	)
Other	209			0.1		(444		)	(0.2	)
Income tax expense (benefit) from continuing operations	$	42,471		18.7		$	61,563		30.5

	Six Months Ended June 30,
	2018			%		2017			%
Expected income taxes	$	92,338		21.0		$	137,783		35.0
Increase (reduction) in income taxes resulting from:
Low income housing investments	(6,649		)	(1.5	)	(9,298		)	(2.4	)
Share-based awards	(4,254		)	(1.0	)	(9,439		)	(2.4	)
Other	167			—		(2,920		)	(0.7	)
Income tax expense (benefit) from continuing operations	$	81,602		18.5		$	116,126		29.5