Capital Stock - Dividends (Details)	1 Months Ended																																					3 Months Ended								12 Months Ended
	Feb. 29, 2016 USD ($) $ / shares	Jan. 31, 2016 USD ($) $ / shares	Dec. 31, 2015 USD ($) $ / shares	Nov. 30, 2015 USD ($) $ / shares	Oct. 31, 2015 USD ($) $ / shares	Sep. 30, 2015 USD ($) $ / shares	Aug. 31, 2015 USD ($) $ / shares	Jul. 31, 2015 USD ($) $ / shares	Jun. 30, 2015 USD ($) $ / shares	May. 31, 2015 USD ($) $ / shares	Apr. 30, 2015 USD ($) $ / shares	Mar. 31, 2015 USD ($) $ / shares	Feb. 28, 2015 USD ($) $ / shares	Jan. 31, 2015 USD ($) $ / shares	Dec. 31, 2014 USD ($) $ / shares	Nov. 30, 2014 USD ($) $ / shares	Oct. 31, 2014 USD ($) $ / shares	Sep. 30, 2014 USD ($) $ / shares	Aug. 31, 2014 USD ($) $ / shares	Jul. 31, 2014 USD ($) $ / shares	Jun. 30, 2014 USD ($) $ / shares	May. 31, 2014 USD ($) $ / shares	Apr. 30, 2014 USD ($) $ / shares	Mar. 31, 2014 USD ($) $ / shares	Feb. 28, 2014 USD ($) $ / shares	Jan. 31, 2014 USD ($) $ / shares	Dec. 31, 2013 USD ($) $ / shares	Nov. 30, 2013 USD ($) $ / shares	Oct. 31, 2013 USD ($) $ / shares	Sep. 30, 2013 USD ($) $ / shares	Aug. 31, 2013 USD ($) $ / shares	Jul. 31, 2013 USD ($) $ / shares	Jun. 30, 2013 USD ($) $ / shares	May. 31, 2013 USD ($) $ / shares	Apr. 30, 2013 USD ($) $ / shares	Mar. 31, 2013 USD ($) $ / shares	Feb. 28, 2013 shares	Dec. 31, 2015 $ / shares	Sep. 30, 2015 $ / shares	Jun. 30, 2015 $ / shares	Mar. 31, 2015 $ / shares	Dec. 31, 2014 $ / shares	Sep. 30, 2014 $ / shares	Jun. 30, 2014 $ / shares	Mar. 31, 2014 $ / shares	Dec. 31, 2015 $ / shares	Dec. 31, 2014 $ / shares	Dec. 31, 2013 $ / shares shares
Cash Dividends [Abstract]
Declaration Date	February 10, 2016	January 11, 2016	December 10, 2015	November 10, 2015	October 8, 2015	September 11, 2015	August 11, 2015	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	December 11, 2013	November 12, 2013	October 10, 2013	September 10, 2013	August 12, 2013	July 9, 2013	June 10, 2013	May 9, 2013	April 10, 2013	March 8, 2013
Record Date	February 24, 2016	January 26, 2016	December 24, 2015	November 24, 2015	October 26, 2015	September 25, 2015	August 26, 2015	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	December 26, 2013	November 25, 2013	October 25, 2013	September 25, 2013	August 26, 2013	July 25, 2013	June 25, 2013	May 28, 2013	April 25, 2013	March 25, 2013
Payment Date	February 29, 2016	January 29, 2016	December 30, 2015	November 30, 2015	October 30, 2015	September 30, 2015	August 31, 2015	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	December 30, 2013	November 27, 2013	October 31, 2013	September 30, 2013	August 30, 2013	July 31, 2013	June 28, 2013	May 31, 2013	April 30, 2013	March 27, 2013
Per Share Amount | $ / shares	$ 0.14	$ 0.14	$ 0.14	$ 0.14	$ 0.14	$ 0.14	$ 0.14	$ 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	$ 0.135	$ 0.135	$ 0.135	$ 0.135	$ 0.135	$ 0.135	$ 0.135	$ 0.135	$ 0.135		$ 0.42	$ 0.42	$ 0.54	$ 0.54	$ 0.54	$ 0.54	$ 0.54	$ 0.54	$ 1.92	$ 2.16	$ 1.395
Total | $	$ 3,049,000	$ 3,049,000	$ 3,048,000	$ 3,051,000	$ 3,051,000	$ 3,069,000	$ 3,132,000	$ 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	$ 603,000	$ 451,000	$ 451,000	$ 451,000	$ 451,000	$ 451,000	$ 451,000	$ 451,000	$ 451,000	$ 451,000
Stock Dividend [Abstract]
Stock Dividend Declaration Date																																					2/14/2013											2/14/2013
Stockholders Equity Note Stock Split Conversion Ratio																																					5.37											5.37
Stock Dividends Shares | shares																																					827,555											827,555
Stock Dividend Issue Date																																					2/20/2013											2/20/2013