Significant Accounting Policies - Impact of New Lease Standard On Balance Sheet Line Items (Details) - USD ($) $ in Millions	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Jan. 01, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Other current assets	$ 4,841			$ 4,533	$ 4,581
Total current assets	48,185			45,195	45,243
Property and equipment, net	11,651			11,360	11,349
Operating lease right-of-use assets	20,757			20,987	0
Intangible assets, net	33,655			36,307	36,524
Other assets	4,385			4,525	5,046
Total assets	220,113			216,668	196,456
Accrued expenses	11,615			10,659	10,711
Current portion of operating lease liabilities	1,798			1,803	0
Current portion of long-term debt	3,778			1,267	1,265
Total current liabilities	52,544			45,762	44,009
Long-term operating lease liabilities	18,826			18,832	0
Long-term debt	64,206			71,348	71,444
Deferred income taxes	7,279			7,740	7,677
Other long-term liabilities	2,178			2,262	2,780
Total liabilities	157,180			157,947	137,913
Retained earnings	44,017			41,089	40,911
Total CVS Health shareholders’ equity	62,614			58,403	58,225
Total shareholders’ equity	$ 62,933	$ 61,599	$ 60,006	58,721	$ 58,543	$ 36,622	$ 35,611	$ 38,677	$ 37,695
Accounting Standards Update 2016-02
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Other current assets				(48)
Total current assets				(48)
Property and equipment, net				11
Operating lease right-of-use assets				20,987
Intangible assets, net				(217)
Other assets				(521)
Total assets				20,212
Accrued expenses				(52)
Current portion of operating lease liabilities				1,803
Current portion of long-term debt				2
Total current liabilities				1,753
Long-term operating lease liabilities				18,832
Long-term debt				(96)
Deferred income taxes				63
Other long-term liabilities				(518)
Total liabilities				20,034
Retained earnings				178
Total CVS Health shareholders’ equity				178
Total shareholders’ equity				$ 178