Basis of Presentation (Earnings per Share) (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Earnings Per Share
Net income attributable to Heartland	$ 12,488	$ 12,841
Preferred dividends and discount	(408)	(1,021)
Net income available to common stockholders	$ 12,080	$ 11,820
Weighted average common shares outstanding for basic earnings per share	16,852	16,490
Assumed incremental common shares issued upon exercise of stock options	335	240
Weighted average common shares for diluted earnings per share	17,187	16,730
Earnings per common share — basic (in dollars per share)	$ 0.72	$ 0.72
Earnings per common share — diluted (in dollars per share)	$ 0.70	$ 0.71
Number of antidilutive stock options excluded from diluted earnings per share computation (in shares)	105	509