Stockholders Equity Dividend (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended					0 Months Ended
	Apr. 30, 2015	Jan. 31, 2015	Oct. 31, 2014	Jul. 31, 2014	Apr. 30, 2014	May 22, 2015
Dividends Payable [Line Items]
Dividends Payable, Date Declared	Feb. 26, 2015	Nov. 20, 2014	Aug. 21, 2014	May 22, 2014	Feb. 27, 2014
Dividends Payable, Date of Record	Mar. 10, 2015	Dec. 10, 2014	Sep. 10, 2014	Jun. 10, 2014	Mar. 10, 2014
Dividends Payable, Date to be Paid	Mar. 31, 2015	Jan. 02, 2015	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014
Cash dividends declared per common share	$ 0.055	$ 0.050	$ 0.050	$ 0.050	$ 0.050
Payments of Dividends	$ 6,383	$ 5,743	$ 5,697	$ 5,693	$ 5,778
Subsequent Event [Member]
Dividends Payable [Line Items]
Dividends Payable, Date Declared						May 22, 2015
Dividends Payable, Date of Record						Jun. 10, 2015
Dividends Payable, Date to be Paid						Jun. 30, 2015
Cash dividends declared per common share						$ 0.055