Components of Income from Discontinued Operations (Parenthetical) (Detail) - USD ($)	3 Months Ended			6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Mar. 31, 2014	Jun. 30, 2015	Jun. 30, 2014
Discontinued Operations And Disposal Groups [Abstract]
Income (loss) from discontinued operations, income taxes	$ 0	$ 0		$ 0	$ 0
Adjustments to amounts reported previously for gain on sale of discontinued operations, income taxes	0	0		0	0
Gain on sale of discontinued operations, income taxes	$ 0	$ 0	$ 0	$ 0	$ 0