Parent Company Only Financial Statements Statements of Income (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Condensed Financial Statements, Captions [Line Items]
Other income									$ 861	$ 1,202	$ 462
Operating expenses	42,405	39,545	41,041	41,957	42,028	36,723	36,199	36,971	164,948	151,921	144,493
Federal income tax benefit	(6,100)	(6,400)	(6,100)	(5,700)	(4,000)	(5,300)	(6,325)	(5,175)	(24,300)	(20,800)	(17,200)
Net Income	14,378	14,993	14,203	13,234	11,662	13,106	13,866	12,374	56,808	51,008	43,050
Chemical Financial Corporation [Member]
Condensed Financial Statements, Captions [Line Items]
Cash dividends from subsidiary bank									24,488	27,550	22,000
Other income									390	92	0
Total income									24,878	27,642	22,000
Operating expenses									4,735	3,773	3,350
Income (loss) before income taxes and equity in undistributed net income of subsidiary bank									20,143	23,869	18,650
Federal income tax benefit									1,556	1,311	1,171
Equity in undistributed net income of subsidiary bank									35,109	25,828	23,229
Net Income									$ 56,808	$ 51,008	$ 43,050