Summary of Significant Accounting Policies Earnings Per Share (Details) - shares	3 Months Ended								12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Accounting Policies [Abstract]
Basic (in shares)	44,499	44,491	44,470	44,447	44,379	44,371	44,354	44,323	44,477,000	44,357,000	44,206,000
Performance shares (in shares)										242,000	221,000
Restricted stock (in shares)										47,000	47,000
Weighted average common shares outstanding - assuming dilution	44,958	44,899	44,470	44,447	44,634	44,716	44,815	44,734	44,477,000	44,646,000	44,474,000