Dividends - Dividends Declared and Paid or Payable (Detail) (USD $)	6 Months Ended	12 Months Ended
	Jun. 30, 2014	Dec. 31, 2013
Dividend per Share	$ 0.14	$ 0.12
Dividend 1 [Member]
Date Declared	Jan. 14, 2014	Jan. 29, 2013
Record Date	Jan. 30, 2014	Feb. 08, 2013
Payment Date	Feb. 14, 2014	Feb. 15, 2013
Dividend per Share	$ 0.07	$ 0.06
Dividend 2 [Member]
Date Declared	Apr. 23, 2014	Apr. 23, 2013
Record Date	May 05, 2014	May 03, 2013
Payment Date	May 15, 2014	May 15, 2013
Dividend per Share	$ 0.07	$ 0.06