Income Tax (Narrative) (Details) (USD $)	3 Months Ended
	Mar. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Income Tax [Abstract]
Foreign withholding tax expense	$ 400,000
Accrued income taxes	16,400,000
Accrued income taxes, current	3,500,000
Non-current tax liabilities	12,900,000
Accrued income taxes, current judgment	3,500,000
Increase to gross unrecognized tax benefits	194,000
Unrecognized tax benefits	2,354,000	2,160,000	2,171,000	1,974,000
Impact of effective tax rate if recognized	1,300,000
Uncertain tax position probable changes in next 12 months, minimum	500,000
Uncertain tax position probable changes in next 12 months, maximum	$ 1,500,000