Stock Plans (LTIP Target Performance Shares) (Details) (Performance Shares [Member])	3 Months Ended	12 Months Ended
	Mar. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Performance Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Balance at beginning of period (in shares)	1,749,000
Shares granted (in shares)	1,028,000	1,124,000	979,000
Shares forfeited (in shares)
Balance at end of period (in shares)	2,777,000	1,749,000