Other Comprehensive Income (Loss) - Additional Information (Detail) - USD ($)	3 Months Ended			6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Mar. 31, 2014	Jun. 30, 2015	Jun. 30, 2014
Amounts Reclassified Out Of Accumulated Other Comprehensive Income Loss [Abstract]
Accumulated other comprehensive income	$ 0	$ 31,000	$ 31,000	$ 11,000	$ 34,000
Effect of disproportionate tax on accumulated other comprehensive income (loss)		$ (16,600,000)			$ (16,600,000)