Share and Unit-Based Plans: Stock Option Activity (Details) (Stock options, USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Stock options
Options
Balance at beginning of year	10,068	12,768	2,700
Granted	0	0	10,068
Exercised	0	(2,700)	0
Balance at end of year	10,068	10,068	12,768
Weighted Average Exercise Price (in dollars per share)
Balance at beginning of year	$ 59.57	$ 54.69	$ 36.51
Granted	$ 0.00	$ 0.00	$ 59.57
Exercised	$ 0.00	$ 36.51	$ 0.00
Balance at end of year	$ 59.57	$ 59.57	$ 54.69