Subsequent Events - Additional Information (Detail) - Dividend Declared [Member] - $ / shares	6 Months Ended
	Jun. 30, 2015	Jul. 28, 2015
Subsequent Event [Line Items]
Date of payment to shareholders entitled to dividends	Sep. 25, 2015
Date of record of shareholders entitled to dividends	Sep. 11, 2015
Subsequent Event [Member]
Subsequent Event [Line Items]
Cash dividend per share		$ 0.15