Consolidated Statements of Financial Position - USD ($) $ in Millions	Sep. 30, 2017	Dec. 31, 2016
Assets
Fixed maturities, available-for-sale (2017 and 2016 include $257.4 million and $232.5 million related to consolidated variable interest entities)	$ 59,137.8	$ 54,846.1
Fixed maturities, trading (2017 and 2016 include $0.0 million and $82.4 million related to consolidated variable interest entities)	232.5	398.4
Equity securities, available-for-sale	118.3	98.9
Equity securities, trading (2017 and 2016 include $788.3 million and $721.9 million related to consolidated variable interest entities)	1,670.9	1,413.4
Mortgage loans	14,020.4	13,230.2
Real estate (2017 and 2016 include $291.9 million and $305.7 million related to consolidated variable interest entities)	1,650.2	1,368.8
Policy loans	812.0	823.8
Other investments (2017 and 2016 include $105.5 million and $89.8 million related to consolidated variable interest entities and $88.9 million and $86.2 million measured at fair value under the fair value option)	3,561.3	3,655.9
Total investments	81,203.4	75,835.5
Cash and cash equivalents	2,795.0	2,719.6
Accrued investment income	634.6	580.6
Premiums due and other receivables	1,516.6	1,361.9
Deferred acquisition costs	3,481.4	3,380.2
Property and equipment	754.6	699.0
Goodwill	1,055.2	1,020.8
Other intangibles	1,314.7	1,325.3
Separate account assets (2017 and 2016 include $39,725.2 million and $35,844.1 million related to consolidated variable interest entities)	154,085.9	139,832.6
Other assets	1,092.2	1,258.8
Total assets	247,933.6	228,014.3
Liabilities
Contractholder funds (2017 and 2016 include $374.5 million and $358.7 million related to consolidated variable interest entities)	38,208.6	37,953.6
Future policy benefits and claims	32,129.1	29,000.7
Other policyholder funds	926.2	890.4
Short-term debt	58.8	51.4
Long-term debt	3,175.4	3,125.7
Income taxes currently payable	53.7	12.9
Deferred income taxes	1,515.2	972.4
Separate account liabilities (2017 and 2016 include $39,725.2 million and $35,844.1 million related to consolidated variable interest entities)	154,085.9	139,832.6
Other liabilities (2017 and 2016 include $259.2 million and $284.1 million related to consolidated variable interest entities, of which $0.0 million and $59.9 million are measured at fair value under the fair value option)	5,584.3	5,783.3
Total liabilities	235,737.2	217,623.0
Redeemable noncontrolling interest (2017 and 2016 include $50.1 million and $58.8 million related to consolidated variable interest entities)	129.1	97.5
Stockholders' equity
Common stock, par value $.01 per share - 2,500.0 million shares authorized, 473.5 million and 469.2 million shares issued, and 288.5 million and 287.7 million shares outstanding in 2017 and 2016	4.7	4.7
Additional paid-in capital	9,886.8	9,686.0
Retained earnings (accumulated deficit)	8,784.6	7,720.4
Accumulated other comprehensive income (loss)	47.0	(675.2)
Treasury stock, at cost (185.0 million and 181.5 million shares in 2017 and 2016)	(6,726.7)	(6,508.6)
Total stockholders' equity attributable to Principal Financial Group, Inc.	11,996.4	10,227.3
Noncontrolling interest	70.9	66.5
Total stockholders' equity	12,067.3	10,293.8
Total liabilities and stockholders' equity	$ 247,933.6	$ 228,014.3