Consolidated Statements of Financial Position - USD ($) $ in Millions	Jun. 30, 2015	Dec. 31, 2014
Assets
Fixed maturities, available-for-sale (2015 and 2014 include $269.5 million and $278.2 million related to consolidated variable interest entities)	$ 48,949.7	$ 49,670.8
Fixed maturities, trading (2015 and 2014 both include $100.4 million related to consolidated variable interest entities)	560.3	604.6
Equity securities, available-for-sale	176.1	123.0
Equity securities, trading (2015 and 2014 include $347.7 million and $345.3 million related to consolidated variable interest entities)	891.8	840.2
Mortgage loans	12,070.7	11,811.6
Real estate (2015 and 2014 include $343.9 million and $284.9 million related to consolidated variable interest entities)	1,435.1	1,344.6
Policy loans	824.9	829.2
Other investments (2015 and 2014 include $37.6 million and $40.6 million related to consolidated variable interest entities and $55.4 million and $127.2 million measured at fair value under the fair value option)	3,268.0	3,209.8
Total investments	68,176.6	68,433.8
Cash and cash equivalents	2,264.4	1,863.9
Accrued investment income	498.7	505.9
Premiums due and other receivables	1,282.7	1,213.0
Deferred acquisition costs	3,162.4	2,993.0
Property and equipment	601.9	590.2
Goodwill	970.7	1,007.4
Other intangibles	1,268.8	1,323.5
Separate account assets (2015 and 2014 include $34,886.5 million and $34,655.4 million related to consolidated variable interest entities)	142,993.6	140,072.8
Other assets	1,050.9	1,083.5
Total assets	222,270.7	219,087.0
Liabilities
Contractholder funds	34,041.8	34,726.7
Future policy benefits and claims	24,952.7	24,036.6
Other policyholder funds	807.0	812.7
Short-term debt	26.6	28.0
Long-term debt (2015 and 2014 include $68.1 million and $82.3 million related to consolidated variable interest entities)	3,315.9	2,531.2
Income taxes currently payable	16.0	11.5
Deferred income taxes	819.7	1,035.3
Separate account liabilities (2015 and 2014 include $34,886.5 million and $34,655.4 million related to consolidated variable interest entities)	142,993.6	140,072.8
Other liabilities (2015 and 2014 include $346.5 million and $344.0 million related to consolidated variable interest entities, of which $66.7 million and $71.0 million are measured at fair value under the fair value option)	5,463.2	5,542.2
Total liabilities	212,436.5	208,797.0
Redeemable noncontrolling interest	71.6	58.0
Stockholders' equity
Common stock, par value $.01 per share - 2,500.0 million shares authorized, 465.0 million and 462.7 million shares issued, and 294.7 million and 293.9 million shares outstanding in 2015 and 2014	4.6	4.6
Additional paid-in capital	9,473.8	9,945.5
Retained earnings (accumulated deficit)	6,547.9	6,114.1
Accumulated other comprehensive income (loss)	(326.6)	50.4
Treasury stock, at cost (170.3 million and 168.8 million shares in 2015 and 2014)	(6,006.3)	(5,930.7)
Total stockholders' equity attributable to Principal Financial Group, Inc.	9,693.4	10,184.0
Noncontrolling interest	69.2	48.0
Total stockholders' equity	9,762.6	10,232.0
Total liabilities and stockholders' equity	$ 222,270.7	$ 219,087.0
Series A
Stockholders' equity
Preferred stock, value
Series B
Stockholders' equity
Preferred stock, value		$ 0.1