Consolidated Statements of Comprehensive Income (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Consolidated Statements of Comprehensive Income
Net income (loss)	$ 252.8	$ 259.1	$ 896.1	$ 685.7
Other comprehensive income (loss), net:
Net unrealized gains (losses) on available-for-sale securities	(73.9)	29.3	296.6	(523.7)
Noncredit component of impairment losses on fixed maturities, available-for-sale	11.0	(2.5)	48.9	(13.1)
Net unrealized gains (losses) on derivative instruments	29.2	(25.1)	42.3	(3.4)
Foreign currency translation adjustment	(195.8)	(33.5)	(208.4)	(169.5)
Net unrecognized postretirement benefit obligation	3.6	13.8	10.7	41.4
Other comprehensive income (loss)	(225.9)	(18.0)	190.1	(668.3)
Comprehensive income (loss)	26.9	241.1	1,086.2	17.4
Comprehensive income (loss) attributable to noncontrolling interest	(2.7)	4.4	23.9	4.4
Comprehensive income (loss) attributable to Principal Financial Group, Inc.	$ 29.6	$ 236.7	$ 1,062.3	$ 13.0