Consolidated Statement of Stockholders' Equity (Parenthetical) - $ / shares	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Dividend on common stock, per share	$ 0.54	$ 0.51	$ 1.08	$ 1.02