Deferred revenue - Deferred revenue rollforward (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	May 02, 2015	May 03, 2014
Sterling Jewelers
Deferred Revenue Warranty [Roll Forward]
ESP deferred revenue, beginning of period	$ 668.9	$ 601.2
Plans sold	69.3	64.2
Revenue recognized	(47.5)	(45.8)
ESP deferred revenue, end of period	690.7	619.6
Zale
Deferred Revenue Warranty [Roll Forward]
ESP deferred revenue, beginning of period	120.3
Plans sold	35.2
Revenue recognized	(26.2)
ESP deferred revenue, end of period	$ 129.3