Significant Accounting Policies (Details) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Weighted Average Number of Shares Outstanding, Basic	43,742	44,152	44,660	44,908	45,212	45,526	45,841	46,201	44,362	45,692	47,211
Incremental Common Shares Attributable to Stock Options									0	1	12
Incremental Common Shares Attributable to Contingently Issuable Shares									110	119	129
Weighted Average Number of Shares, Restricted Stock									128	182	201
Weighted Average Number of Shares Outstanding, Diluted	43,927	44,381	44,910	45,182	45,517	45,828	46,128	46,493	44,600	45,994	47,553