Supplemental Cash Flow Information (Details) (USD $)	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Schedule of Supplemental cash flow information
Interest paid	$ 3,784,000	$ 4,092,000
Income taxes paid, net	8,713,000	2,715,000
Foreign tax withholding on dividends declared	$ 3,200,000