Income Taxes (Details 4) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012
Summary of activities related to unrecognized tax benefits
Balance at the beginning of the period	$ 19,466,000	$ 19,583,000
Additions to tax positions related to the current year	3,901,000	3,489,000
Additions to tax positions related to prior years	0	59,000
Subtractions to tax positions related to prior years	(513,000)	(968,000)
Subtractions to tax positions related to settlements	0	(47,000)
Subtractions to tax positions as a result of the lapse of the statute of limitations	(948,000)	(2,650,000)
Balance at the end of the period	21,906,000	19,466,000
Unrecognized tax benefits that, if recognized, would reduce annual effective tax rate	20,400,000	17,900,000
Accrued interest related to unrecognized tax benefits	400,000
Expected increase in unrecognized tax benefits during next fiscal year	$ 1,000,000