Shareholders' Equity (Common Stock) (Details) (USD $) In Millions, except Share data, unless otherwise specified	0 Months Ended		1 Months Ended	3 Months Ended					1 Months Ended
	Feb. 04, 2013	Jul. 19, 2012	Mar. 31, 2012	May 04, 2013	Feb. 02, 2013	Sep. 27, 2012	Jul. 17, 2012	Apr. 28, 2012	Mar. 31, 2012 Performance Based Vesting Schedule [Member]	May 14, 2013 Subsequent Event [Member]
Class of Stock [Line Items]
Options cancelled (shares)			2,020,620						1,010,310
Restricted stock units vesting percentage (percent)			33.00%
Restricted stock units, reminaing percentage to vest (percent)				67.00%
Compensation expense			$ 17.4
Expenses on date of modification			5.3
Vesting period from the date of grant (years)			2 years
Reverse stock split ratio							0.3460
Common stock, shares authorized				120,000,000	120,000,000		120,000,000	120,000,000
Preferred stock dividend, percentage		8.00%
Number of shares of common stock reserved for issuance (years)						500,000
Discount on common stock fair value for employee purchases (percent)						10.00%
Initial public offering shares	13,012,250
Initial public offering shares price per share	$ 35.65
Underwriters discount and legal, accounting, and other expenses	1.0
Secondary stock offering, shareholder shares to be sold (shares)										8,563,172
Secondary stock offering, maximum number of additional shareholder shares to be sold for overallotment of shares (shares)										1,284,475
Estimated stock offering expenses payable										$ 1.0