Parent Company Only Financial Statements Financial Position (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Assets [Abstract]
Investment securities available-for-sale	$ 684,570	$ 586,809
Premises and equipment	75,308	75,458
Goodwill	120,164	120,164
Other assets	132,781	132,412
Total Assets	6,184,708	5,917,252
Liabilities and Equity [Abstract]
Other liabilities	38,395	54,716
Shareholders' equity	696,500	596,341	571,729	560,078
Total Liabilities and Shareholders' Equity	6,184,708	5,917,252
Chemical Financial Corporation [Member]
Assets [Abstract]
Cash at subsidiary bank	65,358	5,960
Investment securities available-for-sale	0	4,755
Investment in subsidiary bank	625,156	579,448
Premises and equipment	3,902	4,309
Goodwill	1,092	1,092
Other assets	3,309	2,598
Total Assets	698,817	598,162
Liabilities and Equity [Abstract]
Other liabilities	2,317	1,821
Shareholders' equity	696,500	596,341
Total Liabilities and Shareholders' Equity	$ 698,817	$ 598,162