Basis of Presentation (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011
Earnings Per Share
Net income attributable to Heartland	$ 13,957	$ 10,221	$ 26,798	$ 14,458
Preferred dividends and discount	(1,021)	(1,336)	(2,042)	(2,672)
Net income available to common stockholders	$ 12,936	$ 8,885	$ 24,756	$ 11,786
Weighted average common shares outstanding for basic earnings per share (in shares)	16,474	16,427	16,482	16,417
Assumed incremental common shares issued upon exercise of stock options (in shares)	244	142	240	144
Weighted average common shares for diluted earnings per share (in shares)	16,718	16,569	16,722	16,561
Earnings per common share — basic	$ 0.79	$ 0.54	$ 1.50	$ 0.72
Earnings per common share — diluted	$ 0.77	$ 0.54	$ 1.48	$ 0.71
Number of antidilutive stock options excluded from diluted earnings per share computation	500	537	500	537