Earnings Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands |
3 Months Ended | 12 Months Ended | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
Dec. 31, 2015 |
Sep. 30, 2015 |
Jun. 30, 2015 |
Mar. 31, 2015 |
Dec. 31, 2014 |
Sep. 30, 2014 |
Jun. 30, 2014 |
Mar. 31, 2014 |
Dec. 31, 2015 |
Dec. 31, 2014 |
Dec. 31, 2013 |
|
| Earnings Per Share [Abstract] | |||||||||||
| Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount | 49,795 | 0 | 96,096 | ||||||||
| Net income | $ 9,638 | $ 27,066 | $ 22,638 | $ 30,046 | $ 21,154 | $ 27,713 | $ 21,911 | $ 31,153 | $ 89,388 | $ 101,931 | $ 78,236 |
| Basic weighted average shares | 196,173,169 | 196,062,348 | 195,747,954 | 195,745,670 | 195,743,154 | 195,743,154 | 195,733,692 | 195,720,894 | 195,933,800 | 195,735,309 | 195,619,943 |
| Incremental Common Shares Attributable to Dilutive Effect of Share-based Payment Arrangements | 2,113,653 | 2,117,623 | 939,141 | ||||||||
| Diluted weighted average shares | 198,076,031 | 198,254,808 | 197,709,082 | 197,773,850 | 197,853,482 | 197,884,029 | 197,827,833 | 197,747,579 | 198,047,453 | 197,852,932 | 196,559,084 |
| Basic net income per share | $ 0.05 | $ 0.14 | $ 0.12 | $ 0.15 | $ 0.11 | $ 0.14 | $ 0.11 | $ 0.16 | $ 0.46 | $ 0.52 | $ 0.40 |
| Diluted net income per share | $ 0.05 | $ 0.14 | $ 0.11 | $ 0.15 | $ 0.11 | $ 0.14 | $ 0.11 | $ 0.16 | $ 0.45 | $ 0.52 | $ 0.40 |