Subsequent Events: (Details) (Subsequent event, USD $) In Millions, except Per Share data, unless otherwise specified	0 Months Ended	9 Months Ended
	Oct. 28, 2014	Sep. 30, 2014
Subsequent event
Subsequent events:
Dividend declared (in dollars per share)	$ 1.1
Dividend declared, date		Oct. 28, 2014
Dividend payable, date		Dec. 10, 2014
Shareholders of record, date		Nov. 10, 2014
Additional amount authorized under stock repurchase program	$ 5,000