Consolidated Statements of Financial Position (USD $) In Millions, unless otherwise specified	Mar. 31, 2014	Dec. 31, 2013
Assets
Fixed maturities, available-for-sale (2014 and 2013 include $279.5 million and $272.0 million related to consolidated variable interest entities)	$ 50,048.1	$ 48,757.1
Fixed maturities, trading (2014 and 2013 both include $110.4 million related to consolidated variable interest entities)	575.3	563.1
Equity securities, available-for-sale	136.1	110.5
Equity securities, trading (2014 and 2013 include $325.5 million and $327.2 million related to consolidated variable interest entities)	724.2	716.9
Mortgage loans	11,478.4	11,533.6
Real estate	1,390.8	1,271.6
Policy loans	843.8	859.7
Other investments (2014 and 2013 include $57.9 million and $68.1 million related to consolidated variable interest entities and $133.6 million and $142.9 million measured at fair value under the fair value option)	2,910.4	2,944.4
Total investments	68,107.1	66,756.9
Cash and cash equivalents	1,393.1	2,371.8
Accrued investment income	540.4	532.1
Premiums due and other receivables	1,199.3	1,241.0
Deferred acquisition costs	3,045.6	3,077.0
Property and equipment	546.0	500.7
Goodwill	1,075.2	1,100.3
Other intangibles	1,421.8	1,459.0
Separate account assets (2014 and 2013 include $32,652.9 million and $32,824.7 million related to consolidated variable interest entities)	132,804.6	130,018.4
Other assets	1,060.8	1,134.2
Total assets	211,193.9	208,191.4
Liabilities
Contractholder funds	35,736.3	35,958.3
Future policy benefits and claims	23,026.2	22,626.2
Other policyholder funds	791.6	758.9
Short-term debt	148.8	150.6
Long-term debt	2,516.0	2,601.4
Income taxes currently payable	6.4	5.2
Deferred income taxes	889.7	824.0
Separate account liabilities (2014 and 2013 include $32,652.9 million and $32,824.7 million related to consolidated variable interest entities)	132,804.6	130,018.4
Other liabilities (2014 and 2013 include $360.2 million and $342.4 million related to consolidated variable interest entities, of which $97.1 million and $104.9 million are measured at fair value under the fair value option)	4,936.2	5,224.2
Total liabilities	200,855.8	198,167.2
Redeemable noncontrolling interest	280.2	247.2
Stockholders' equity
Common stock, par value $.01 per share - 2,500.0 million shares authorized, 460.9 million and 459.3 million shares issued, and 294.8 million and 295.2 million shares outstanding in 2014 and 2013	4.6	4.6
Additional paid-in capital	9,813.1	9,798.9
Retained earnings (accumulated deficit)	5,605.3	5,405.4
Accumulated other comprehensive income (loss)	361.8	183.2
Treasury stock, at cost (166.1 million and 164.1 million shares in 2014 and 2013)	(5,797.0)	(5,708.0)
Total stockholders' equity attributable to Principal Financial Group, Inc.	9,987.9	9,684.2
Noncontrolling interest	70.0	92.8
Total stockholders' equity	10,057.9	9,777.0
Total liabilities and stockholders' equity	211,193.9	208,191.4
Series A
Stockholders' equity
Preferred stock, value
Total stockholders' equity	0	0
Series B
Stockholders' equity
Preferred stock, value	0.1	0.1
Total stockholders' equity	$ 0.1	$ 0.1