Consolidated Statements of Comprehensive Income - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Consolidated Statements of Comprehensive Income
Net income (loss)	$ 300.9	$ 252.8	$ 994.9	$ 896.1
Other comprehensive income (loss), net:
Net unrealized gains (losses) on available-for-sale securities	28.3	(73.9)	(221.0)	296.6
Noncredit component of impairment losses on fixed maturities, available-for-sale	1.0	11.0	17.9	48.9
Net unrealized gains (losses) on derivative instruments	10.3	29.2	22.0	42.3
Foreign currency translation adjustment	(263.2)	(195.8)	(438.3)	(208.4)
Net unrecognized postretirement benefit obligation	11.9	3.6	35.9	10.7
Other comprehensive income (loss)	(211.7)	(225.9)	(583.5)	190.1
Comprehensive income (loss)	89.2	26.9	411.4	1,086.2
Comprehensive income (loss) attributable to noncontrolling interest	(13.8)	(2.7)	(4.5)	23.9
Comprehensive income (loss) attributable to Principal Financial Group, Inc.	$ 103.0	$ 29.6	$ 415.9	$ 1,062.3