CONSOLIDATED STATEMENTS OF CHANGES IN STOCKHOLDERS' EQUITY (Parenthetical) - $ / shares	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015	Dec. 31, 2015
Statement of Stockholders' Equity [Abstract]
Cumulative dividends declared per common share	$ 0.23	$ 0.18	$ 0.65	$ 0.54	$ 0.72