Consolidated Statement of Stockholders' Equity (Parenthetical) - $ / shares	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Dividend on common stock, per share	$ 0.54	$ 0.51	$ 1.62	$ 1.53