Stockholders Equity Dividend (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								9 Months Ended
	Jan. 31, 2017	Oct. 31, 2016	Jul. 31, 2016	Apr. 30, 2016	Jan. 31, 2016	Oct. 31, 2015	Jul. 31, 2015	Apr. 30, 2015	Oct. 31, 2016	Oct. 31, 2015
Dividends Payable [Line Items]
Dividends payable, date declared		Aug. 18, 2016	May 19, 2016	Mar. 03, 2016	Nov. 19, 2015	Aug. 20, 2015	May 22, 2015	Feb. 26, 2015
Dividends payable, date of record		Sep. 19, 2016	Jun. 10, 2016	Mar. 10, 2016	Dec. 15, 2015	Sep. 10, 2015	Jun. 10, 2015	Mar. 10, 2015
Dividends payable, date to be paid		Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Jan. 04, 2016	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015
Cash dividends declared per common share		$ 0.055	$ 0.055	$ 0.055	$ 0.055	$ 0.055	$ 0.055	$ 0.055	$ 0.165	$ 0.165
Payments of dividends		$ 6,016	$ 5,886	$ 5,880	$ 6,326	$ 6,491	$ 6,389	$ 6,383	$ 17,782	$ 19,263
Subsequent Event [Member]
Dividends Payable [Line Items]
Dividends payable, date declared	Nov. 22, 2016
Dividends payable, date of record	Dec. 08, 2016
Dividends payable, date to be paid	Jan. 03, 2017
Cash dividends declared per common share	$ 0.055