Consolidated Statements of Financial Position (USD $) In Millions	Sep. 30, 2011	Dec. 31, 2010
Assets
Fixed maturities, available-for-sale (2011 and 2010 include $225.7 million and $257.9 million related to consolidated variable interest entities)	$ 49,069.5	$ 48,636.3
Fixed maturities, trading (2011 and 2010 include $135.0 million and $131.4 million related to consolidated variable interest entities)	1,278.6	1,120.3
Equity securities, available-for-sale	120.5	169.9
Equity securities, trading (2011 and 2010 include $164.8 million and $158.6 million related to consolidated variable interest entities)	360.3	316.9
Mortgage loans	10,860.4	11,125.1
Real estate	1,013.2	1,063.5
Policy loans	883.5	903.9
Other investments (2011 and 2010 include $105.6 million and $128.7 million related to consolidated variable interest entities, of which $104.5 million and $128.3 million are measured at fair value under the fair value option)	3,202.8	2,641.6
Total investments	66,788.8	65,977.5
Cash and cash equivalents (2011 and 2010 include $304.9 million and $100.0 million related to consolidated variable interest entities)	1,434.2	1,877.4
Accrued investment income	663.7	666.1
Premiums due and other receivables	1,237.4	1,063.0
Deferred policy acquisition costs	3,245.5	3,529.8
Property and equipment	448.2	458.7
Goodwill	413.9	345.4
Other intangibles	872.8	834.6
Separate account assets	67,145.8	69,555.3
Other assets	1,052.0	1,323.3
Total assets	143,302.3	145,631.1
Liabilities
Contractholder funds	36,875.0	37,301.1
Future policy benefits and claims	19,821.9	20,046.3
Other policyholder funds	549.7	592.2
Short-term debt	73.8	107.9
Long-term debt	1,570.4	1,583.7
Income taxes currently payable	2.8	6.2
Deferred income taxes	707.9	409.9
Separate account liabilities	67,145.8	69,555.3
Other liabilities (2011 and 2010 include $515.7 million and $433.6 million related to consolidated variable interest entities, of which $90.6 million and $114.5 million are measured at fair value under the fair value option)	6,265.6	6,143.5
Total liabilities	133,012.9	135,746.1
Stockholders' equity
Common stock, par value $.01 per share - 2,500.0 million shares authorized, 450.2 million and 448.5 million shares issued, and 305.1 million and 320.4 million shares outstanding in 2011 and 2010	4.5	4.5
Additional paid-in capital	9,617.9	9,563.8
Retained earnings (deficit)	5,130.3	4,612.3
Accumulated other comprehensive income (loss)	409.2	272.4
Treasury stock, at cost (145.1 million and 128.1 million shares in 2011 and 2010)	(5,181.7)	(4,725.3)
Total stockholders' equity attributable to Principal Financial Group, Inc.	9,980.3	9,727.8
Noncontrolling interest	309.1	157.2
Total stockholders' equity	10,289.4	9,885.0
Total liabilities and stockholders' equity	143,302.3	145,631.1
Series A
Stockholders' equity
Preferred stock, value
Series B
Stockholders' equity
Preferred stock, value	$ 0.1	$ 0.1