Consolidated Statements of Comprehensive Income (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Consolidated Statements of Comprehensive Income
Net income (loss)	$ 324.1	$ 190.0
Other comprehensive income (loss), net:
Net unrealized gains (losses) on available-for-sale securities	192.2	(99.3)
Noncredit component of impairment losses on fixed maturities, available-for-sale	17.5	(11.3)
Net unrealized gains (losses) on derivative instruments	9.0	22.0
Foreign currency translation adjustment	(45.6)	54.4
Net unrecognized postretirement benefit obligation	3.5	13.8
Other comprehensive income (loss)	176.6	(20.4)
Comprehensive income (loss)	500.7	169.6
Comprehensive income (loss) attributable to noncontrolling interest	20.2	2.4
Comprehensive income (loss) attributable to Principal Financial Group, Inc.	$ 480.5	$ 167.2