Initial Public Offering of Blackhawk Network Holdings, Inc. ("Blackhawk") (Details) (IPO [Member], Blackhawk Network Holdings, Inc. [Member], Class A Common Stock [Member], USD $) In Millions, except Per Share data, unless otherwise specified	0 Months Ended
	Apr. 24, 2013
IPO [Member] | Blackhawk Network Holdings, Inc. [Member] | Class A Common Stock [Member]
Class of Stock [Line Items]
Sale of stock, number of shares available	11.5
Sale of stock, price per share	$ 23
Sale of stock, number of shares of exercised, underwriter options	1.5
Sale of stock, number of shares issued in transaction	11.3
Sale of stock, gross proceeds	$ 243.6
Sale of stock, consideration received on transaction	237.9
Sale of stock, percentage of ownership before transaction	95.00%
Sale of stock, percentage of ownership after transaction	73.00%
Income tax due on sales of stock	$ 82.3