Capital Stock - Dividends (Details) - USD ($)	1 Months Ended																									3 Months Ended		6 Months Ended
	Jul. 31, 2015	Jun. 30, 2015	May. 31, 2015	Apr. 30, 2015	Mar. 31, 2015	Feb. 28, 2015	Jan. 31, 2015	Dec. 31, 2014	Nov. 30, 2014	Oct. 31, 2014	Sep. 30, 2014	Aug. 31, 2014	Jul. 31, 2014	Jun. 30, 2014	May. 31, 2014	Apr. 30, 2014	Mar. 31, 2014	Feb. 28, 2014	Jan. 31, 2014	Dec. 31, 2013	Nov. 30, 2013	Oct. 31, 2013	Sep. 30, 2013	Aug. 31, 2013	Jul. 31, 2013	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Cash Dividends [Abstract]
Declaration Date	July 9, 2015	June 9, 2015	May 11, 2015	April 9, 2015	March 10, 2015	February 10, 2015	January 13, 2015	December 9, 2014	November 12, 2014	October 9, 2014	September 9, 2014	August 12, 2014	July 10, 2014	June 11, 2014	May 8, 2014	April 8, 2014	March 11, 2014	February 11, 2014	January 9, 2014	June 11, 2014	May 8, 2014	April 8, 2014	March 11, 2014	February 11, 2014	January 9, 2014
Record Date	July 27, 2015	June 22, 2015	May 26, 2015	April 27, 2015	March 27, 2015	February 25, 2015	January 26, 2015	December 26, 2014	November 25, 2014	October 28, 2014	September 25, 2014	August 26, 2014	July 28, 2014	June 25, 2014	May 27, 2014	April 25, 2014	March 26, 2014	February 25, 2014	January 27, 2014	June 25, 2014	May 27, 2014	April 25, 2014	March 26, 2014	February 25, 2014	January 27, 2014
Payment Date	July 31, 2015	June 30, 2015	May 29, 2015	April 30, 2015	March 31, 2015	February 27, 2015	January 30, 2015	December 30, 2014	November 28, 2014	October 31, 2014	September 30, 2014	August 29, 2014	July 31, 2014	June 30, 2014	May 30, 2014	April 30, 2014	March 31, 2014	February 28, 2014	January 31, 2014	June 30, 2014	May 30, 2014	April 30, 2014	March 31, 2014	February 28, 2014	January 31, 2014
Per Share Amount	$ 0.14	$ 0.18	$ 0.18	$ 0.18	$ 0.18	$ 0.18	$ 0.18	$ 0.18	$ 0.18	$ 0.18	$ 0.18	$ 0.18	$ 0.18	$ 0.18	$ 0.18	$ 0.18	$ 0.18	$ 0.18	$ 0.18	$ 0.18	$ 0.18	$ 0.18	$ 0.18	$ 0.18	$ 0.18	$ 0.54	$ 0.54	$ 1.08	$ 1.08
Total	$ 3,218,000	$ 4,057,000	$ 3,580,000	$ 3,303,000	$ 3,205,000	$ 3,017,000	$ 3,017,000	$ 3,004,000	$ 2,737,000	$ 2,358,000	$ 2,348,000	$ 1,999,000	$ 1,759,000	$ 1,712,000	$ 1,641,000	$ 1,636,000	$ 1,550,000	$ 974,000	$ 925,000	$ 1,712	$ 1,641	$ 1,636	$ 1,550	$ 974	$ 925