Common Stock Options (Narrative) (Details) (USD $)	1 Months Ended	3 Months Ended		0 Months Ended	3 Months Ended
	Mar. 31, 2012	May 04, 2013	Apr. 28, 2012	Aug. 25, 2010 2002 Equity Incentive Plan [Member]	May 04, 2013 2002 Equity Incentive Plan [Member]	Jul. 24, 2012 2002 Equity Incentive Plan [Member]	May 04, 2013 Restricted Shares [Member]	Feb. 02, 2013 Restricted Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock options and restricted shares available for grant (shares)						7,600,000
Stock option maximum term (years)					10 years
Vesting period from the date of grant (years)	2 years				4 years
Shares available for issuance (shares)					4,873,709
Period following board of directors resolution for exercise of options outstanding (days)				20 days
Deposit liability							$ 228,000	$ 308,000
Weighted average grant-date fair value of stock options granted (dollars per share)		$ 18.15	$ 4.36
Unrecognized compensation costs related to non-vested share-based compensation		$ 13,300,000
Unrecognized compensation costs related to nonvested share-based compensation, recognition period (years)		2 years